The symbiotic relationship between humans and their intestinal microbiome is supported by urea nitrogen salvaging. Previous studies have shown that colonic UT‐B urea transporters play a significant role in this important physiological process.
This current study investigated UT‐A and UT‐B urea transporter expression along the human gastrointestinal tract.
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Using western blotting experiments, a strong 40–60 kDa UT‐B signal was found to be abundant in both ileum and colon Physiological data and to prepare the report on the experiment. In order to count average red and white blood cell number, cells have to be treated with a..
Importantly, this signal was deglycosylated by PNGaseF enzyme treatment to a core protein of 30 kDa in both tissues.
Further immunolocalization studies revealed UT‐B transporter proteins were present at the apical membrane of the villi in the ileum, but predominantly at the basolateral membrane of the colonic surface epithelial cells. Finally, a blind scoring immunolocalization study suggested that there was no significant difference in UT‐B abundance throughout the colon (NS, ANOVA, N = 5–21).
In conclusion, this current study suggested UT‐B to be the main human intestinal urea transporter. Intriguingly, these data suggested that the same UT‐B isoform was present in all intestinal epithelial cells, but that the precise cellular location varied.
UT‐B urea transporter RNA was expressed all along the human gastrointestinal tract, with a glycosylated 40–60 kDa UT‐B protein being abundant. This UT‐B protein was localized to the apical membrane of ileum villi cells and the basolateral region of colonic surface epithelial cells.
Low serum CC16 levels are associated with accelerated lung function decline in human population studies, but it is not known whether low serum CC16 levels contribute to lung function decline, or are an epiphenomenon. We tested the hypothesis that unchallenged Cc16-/- mice develop accelerated rates of pulmonary function test abnormalities and pulmonary pathologies over time compared with unchallenged WT mice.
Respiratory mechanics, airspace enlargement, and small airway fibrosis were measured in unchallenged wild-type (WT) versus Cc16-/- mice over 6-18 months of age. Lung leukocyte counts and lung levels of metalloproteinases (Mmps), cytokines, oxidative stress, cellular senescence markers (p19 and p21), and lung cell apoptosis, and serum C-reactive protein (CRP) levels were measured in age-matched WT versus Cc16-/- mice.
Unchallenged Cc16-/- mice developed greater increases in lung compliance, airspace enlargement, and small airway fibrosis than age-matched WT mice over 6-18 months of age. Cc16-/- mice had greater: (1) lung leukocyte counts; (2) lung levels of Ccl2, Ccl-5, interleukin-10, Mmp-2, and Mmp-9; (3) pulmonary oxidative stress levels, (4) alveolar septal cell apoptosis and staining for p16 and p21; and (5) serum CRP levels.
Unchallenged Cc16-/- mice had greater nuclear factor- B (NF- B) activation in their lungs than age-matched WT mice, but similar lung levels of secretory phospholipase-A2 activity. Cc16 deficiency in mice leads spontaneously to an accelerated lung aging phenotype with exaggerated pulmonary inflammation and COPD-like lung pathologies associated with increased activation of NF- B in the lung.
CC16 augmentation strategies may reduce lung aging in CC16-deficient individuals. In response to stimulation of the nasal passages with volatile ammonia vapors, the nasopharyngeal reflex produces parasympathetically mediated bradycardia, sympathetically mediated increased peripheral vascular tone, and apnea.
The anterior ethmoidal nerve (AEN), which innervates the anterior nasal mucosa, is thought to be primarily responsible for providing the sensory afferent signals that initiate these protective reflexes, as bilateral sectioning causes an attenuation of this response. However, recent evidence has shown cardiovascular responses to nasal stimulation with ammonia vapors are fully intact 9 days after bilateral AEN sectioning, and are similar to control animals without bilaterally sectioned AENs.
To investigate this restoration of the nasopharyngeal response, we recorded the cardiorespiratory responses to nasal stimulation with ammonia vapors immediately after, and 3 and 9 days after, bilateral AEN sectioning. We also processed brainstem tissue for Fos to determine how the restoration of the nasopharyngeal response would affect the activity of neurons in the medullary dorsal horn (MDH), the part of the ventral spinal trigeminal nucleus caudalis region that receives primary afferent signals from the nose and nasal passages.
We found 3 days after bilateral AEN sectioning the cardiorespiratory responses to nasal stimulation are partially restored. The bradycardic response to nasal stimulation is significantly more intense 3 days after AEN sectioning compared to Acute AEN sectioning.
Surprisingly, 3 days after AEN sectioning the number of Fos‐positive neurons within MDH decreased, even though the cardiorespiratory responses to nasal stimulation intensified. Collectively these findings indicate that, besides the AEN, there are alternate sensory pathways that can activate neurons within the trigeminal nucleus in response to nasal stimulation.
The findings further suggest trigeminal neuronal plasticity involving these alternate sensory pathways occurs in as few as 3 days after bilateral AEN sectioning. Finally, activation of even a significantly reduced number of MDH neurons is sufficient to initiate the nasopharyngeal response.
The nasopharyngeal response, like the diving response, produces bradycardia, increased sympathetic tone, decreased respiratory rate, and apnea. The anterior ethmoidal nerve (AEN), which innervates the nasal passages, is thought to be important for initiating these reflexes, as cutting the nerve bilaterally significantly attenuates the cardiorespiratory responses.
However, waiting 9 days, or as few as 3 days, after AEN sectioning sees a restoration of the bradycardia and apnea. The findings suggest other trigeminal nerves also innervate the nasal passages, and neuronal plasticity within the trigeminal nucleus enables restoration of the nasopharyngeal response after bilateral AEN sectioning.
Whether the large lungs of swimmers result from intensive training or genetic endowment has been widely debated. Given that peak lung growth velocities occur during puberty, this study examined if competitive swimming during puberty affected lung growth.
Eleven- to fourteen-year-old healthy female competitive swimmers and controls were assessed before (PRE) and after (POST) one swimming season (7. Pulmonary function testing included lung volumes, spirometry, diffusion capacity (DL,CO ), and maximal inspiratory (PIMAX ) and expiratory (PEMAX ) pressures.
Ventilatory constraints, including end-expiratory lung volume, expiratory flow limitation, and utilization of ventilatory capacity, were assessed during an incremental cycling test. Swimmers (n = 11) and controls (n = 10) were of similar age, size, and sexual maturity (P >0.
However, swimmers compared to controls had a greater total lung capacity (PRE 4.
01), differences were attenuated when expressed relative to alveolar volume (PRE 5. The groups achieved a similar maximal oxygen uptake (P = 0. 32), and ventilatory constraints experienced were not different (P >0.
Changes over time were not different between groups (P >0.
At the initial measurement, pubertal female swimmers had greater lung size, expiratory flows, and indices of respiratory muscle strength, but similar ventilatory constraints while cycling.
One competitive swimming season did not further accentuate this enhanced lung size and function or alter ventilatory mechanics, suggesting that competitive swimming during puberty did not affect lung growth. Calmodulin (CaM) and S100A1 fine-tune skeletal muscle Ca2+ release via opposite modulation of the ryanodine receptor type 1 (RyR1).
Binding to and modulation of RyR1 by CaM and S100A1 occurs predominantly at the region ranging from amino acid residue 3614-3640 of RyR1 (here referred to as CaMBD2). Using synthetic peptides, it has been shown that CaM binds to two additional regions within the RyR1, specifically residues 1975-1999 and 4295-4325 (CaMBD1 and CaMBD3, respectively).
Because S100A1 typically binds to similar motifs as CaM, we hypothesized that S100A1 could also bind to CaMBD1 and CaMBD3.
Our goals were: (1) to establish whether S100A1 binds to synthetic peptides containing CaMBD1 and CaMBD3 using isothermal calorimetry (ITC), and (2) to identify whether S100A1 and CaM modulate RyR1 Ca2+ release activation via sites other than CaMBD2 in RyR1 in its native cellular context 2 May 2007 - Lead for Physiological Measurement, Department of Health. Physiological new emphasis to the range of skills needed across the in order to deliver 18 week pathways. The or in reporting and interpreting). In some..
We developed the mouse model (RyR1D-S100A1KO), which expresses point mutation RyR1-L3625D (RyR1D) that disrupts the modulation of RyR1 by CaM and S100A1 at CaMBD2 and also lacks S100A1 (S100A1KO).
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Using high-speed Ca2+ imaging and a model for Ca2+ binding and transport, we show that the RyR1D-S100A1KO muscle fibers exhibit a modest but significant increase in myoplasmic Ca2+ transients and enhanced Ca2+ release flux following field stimulation when compared to fibers from RyR1D mice, which were used as controls to eliminate any effect of binding at CaMBD2, but with preserved S100A1 expression. Our results suggest that S100A1, similar to CaM, binds to CaMBD1 and CaMBD3 within the RyR1, but that CaMBD2 appears to be the primary site of RyR1 regulation by CaM and S100A1.
Diet-induced obesity is associated with hepatic steatosis, which has been linked with activation of the unfolded protein response (UPR). PGC-1 is a transcriptional coactivator involved in exercise training-induced adaptations in muscle and liver.
Therefore, the aim of this study was to test the hypothesis that PGC-1 is required for exercise training-mediated prevention of diet-induced steatosis and UPR activation in liver. Male liver-specific PGC-1 knockout (LKO) and littermate floxed (lox/lox) mice were divided into two groups receiving either control diet (CON) or high-fat high-fructose diet (HFF).
After 9 weeks, half of the HFF mice were treadmill exercise trained for 4 weeks (HFF+ExT), while the rest were kept sedentary. HFF resulted in increased body and liver weight, adiposity, hepatic steatosis and whole body glucose intolerance as well as decreased hepatic IRE1 phosphorylation.
Exercise training prevented the HFF-induced weight gain and partially prevented increased liver weight, adiposity and glucose intolerance, but with no effect on liver triglycerides. In addition, BiP protein and CHOP mRNA content increased with exercise training compared with CON and HFF, respectively.
Lack of PGC-1 in the liver only resulted in minor changes in the PERK pathway. In conclusion, this study provides evidence for dissociation between diet-induced hepatic triglyceride accumulation and hepatic UPR activation.
In addition, PGC-1 was not required for maintenance of basal UPR in the liver and due to only minor exercise training effects on UPR further studies are needed to conclude on the potential role of PGC-1 in exercise training-induced adaptations in hepatic UPR. We tested whether dietary fatty acids alter membrane composition shifting localization of signaling pathways within caveolae to determine their role in vascular function.
Wild type (WT) and caveolin‐1‐deficient mice (cav‐1 KO), required for vascular caveolae formation, were fed low fat (LF), high saturated fat (HF, 60% kcal from lard), or high‐fat diet with 50:50 lard and n‐3 polyunsaturated fatty acid‐enriched menhaden oil (MO). HF and MO increased body weight and fat in WT but had less effect in cav‐1 KO.
MO increased unsaturated fatty acids and the unsaturation index of aorta from WT and cav‐1 KO. In LF WT aorta, endothelial nitric oxide synthase (eNOS) was localized to cav‐1‐enriched low‐density fractions which shifted to actin‐enriched high‐density fractions with acetylcholine (ACh).
HF and MO shifted eNOS to high‐density fractions in WT aorta which was not affected by ACh. In cav‐1 KO aorta, eNOS was localized in low‐density non‐caveolar fractions but not shifted by ACh or diet.
Inducible NOS and cyclooxygenase 1/2 were not localized in low‐density fractions or affected by diet, ACh or genotype. ACh‐induced dilation of gracilis arteries from HF WT was similar to dilation in LF but the NOS component was reduced.
In WT and cav‐1 KO, dilation to ACh was enhanced by MO through increased role for NOS and cyclooxygenase. We conclude that dietary fats affect vascular fatty acid composition and membrane localization of eNOS but the contribution of eNOS and cyclooxygenase in ACh‐mediated vascular responses is independent of lipid rafts.
Although dietary fatty acids affect the composition of fatty acids and localization of eNOS in lipid rafts within vasculature, the effects on eNOS localization did not account for changes in mechanisms underlying dilation to acetylcholine. Dietary n‐3 polyunsaturated fatty acids markedly augment the contribution from both eNOS and cyclooxygenase in dilation of gracilis arteries to acetylcholine.
A low‐protein high carbohydrate (LPHC) diet and a high‐protein low carbohydrate (HPLC) diet have been reported to positively and negatively regulate whole‐body glucose tolerance and insulin sensitivity, respectively. Skeletal muscle is quantitatively the most important tissue clearing glucose in the postprandial state, but it is unclear if LPHC and HPLC diets directly influence insulin action in skeletal muscle.
To test this, mice were placed on control chow diet, LPHC and HPLC diets for 13. 5 weeks at which time the submaximal insulin‐stimulated glucose transport and insulin signaling were evaluated in ex vivo incubated oxidative soleus and glycolytic EDL muscle.
At the whole‐body level, the diets had the anticipated effects, with LPHC diet improving glucose tolerance and insulin‐sensitivity whereas HPLC diet had the opposite effect. However, neither insulin‐stimulated Akt/TBC1D4 signaling and glucose transport ex vivo, nor cell signaling in vivo were altered by the diets.
These data imply that skeletal muscle insulin sensitivity does not contribute to the whole‐body effects of LPHC and HPLC diets on glucose metabolism. Chronic low protein/high carbohydrate diet augments and high protein/low/carbohydrate diet lowers whole‐body insulin sensitivity.
This occurs independently of skeletal muscle cell signaling or insulin action. Brugada syndrome (BrS) is an inherited disease associated with ST elevation in the right precordial leads, polymorphic ventricular tachycardia (PVT), and sudden cardiac death in adults.
Mutations in the cardiac sodium channel account for a large fraction of BrS cases. BrS manifests in the right ventricle (RV), which led us to examine the biophysical and molecular properties of sodium channel in myocytes isolated from the left (LV) and right ventricle.
Patch clamp was used to record sodium current (INa) in single canine RV and LV epicardial (epi) and endocardial (endo) myocytes. Action potentials were recorded from multicellular preparations and single cells.
mRNA and proteins were determined using quantitative RT‐PCR and Western blot. Although LV wedge preparations were thicker than RV wedges, transmural ECG recordings showed no difference in the width of the QRS complex or transmural conduction time.
Action potential characteristics showed RV epi and endo had a lower Vmax compared with LV epi and endo cells. Peak INa density was significantly lower in epi and endo RV cells compared with epi and endo LV cells.
Recovery from inactivation of INa in RV cells was slightly faster and half maximal steady‐state inactivation was more positive. 2 and 4 mRNA was detected at very low levels in both ventricles, which was confirmed at the protein level.
Our observations demonstrate that Vmax and Na+ current are smaller in RV, presumably due to differential Nav1. These results provide a potential mechanism for the right ventricular manifestation of BrS. This manuscript describes the biophysical differences in cardiac sodium current between the right and left ventricles.
We further show the molecular basis for these observed differences and suggest the physiological and clinical implications of a reduced sodium current in the right ventricle. The DMH is known to regulate brown adipose tissue (BAT) thermogenesis via projections to sympathetic premotor neurons in the raphe pallidus, but there is evidence that the periaqueductal gray (PAG) is also an important relay in the descending pathways regulating thermogenesis.
The anatomical projections from the DMH to the PAG subdivisions and their function are largely elusive, and may differ per anterior–posterior level from bregma. We here aimed to investigate the anatomical projections from the DMH to the PAG along the entire anterior–posterior axis of the PAG, and to study the role of these projections in thermogenesis in Wistar rats.
Anterograde channel rhodopsin viral tracing showed that the DMH projects especially to the dorsal and lateral PAG. Retrograde rabies viral tracing confirmed this, but also indicated that the PAG receives a diffuse input from the DMH and adjacent hypothalamic subregions.
We aimed to study the role of the identified DMH to PAG projections in thermogenesis in conscious rats by specifically activating them using a combination of canine adenovirus‐2 (CAV2Cre) and Cre‐dependent designer receptor exclusively activated by designer drugs (DREADD) technology. Chemogenetic activation of DMH to PAG projections increased BAT temperature and core body temperature, but we cannot exclude the possibility that at least some thermogenic effects were mediated by adjacent hypothalamic subregions due to difficulties in specifically targeting the DMH and distinct subdivisions of the PAG because of diffuse virus expression.
To conclude, our study shows the complexity of the anatomical and functional connection between the hypothalamus and the PAG, and some technical challenges in studying their connection. We mapped projections from the hypothalamus to the periaquaductal grey area.
Chemogenetic activation of this projection increased thermogenesis in rats. Western style, high‐fat diet (HFD) and associated high lipid levels have deleterious effects on fetal and placental development independent of maternal obesity and/or diabetes.
Our objectives were to determine whether HFD without development of obesity would alter amniotic fluid volume (AFV) and amnion aquaporin (AQP) expression in a non‐human primate model. Japanese macaques were fed either a control diet or HFD before and during pregnancy.
The four quadrant amniotic fluid index (AFI) was used as an ultrasonic estimate of AFV at 120 days gestation. Amnion samples were collected at 130 days gestation by cesarean section and AQP mRNA levels were determined by quantitative RT‐PCR.
Similar to that in human, AQP1, AQP3, AQP8, AQP9, and AQP11 were expressed in the macaque amnion with significant differences in levels among AQPs. In macaque, neither individual AQPs nor expression profiles of the five AQPs differed between control and non‐obese HFD animals.
There were regional differences in AQP expression in that, AQP1 mRNA levels were highest and AQP8 lowest in reflected amnion while AQP3, AQP9, and AQP11 were not different among amnion regions. When subdivided into control and HFD groups, AQP1 mRNA levels remain highest in the reflected amnion of both groups.
The HFD did not significantly affect the AFI, but AFI was positively correlated with AQP11 mRNA levels independent of diet. Collectively, these data suggest that HFD in pregnant non‐obese individuals may have at most modest effects on AFV as the AFI and amnion AQP expression are not substantially altered.
In a macaque high‐fat diet (HFD) model, five aquaporins (AQPs) are expressed in placental and reflected amnion with AQP1 levels highest and AQP8 lowest. HFD increased AQP1 and AQP8 mRNA levels but did not affect amniotic fluid index.
This suggests that a diet high in fat during pregnancy may have modest effects on amniotic fluid volume. Cognitive testing with transcranial Doppler ultrasonography (TCD) has been used to assess neurovascular coupling (NVC), but few studies address its multiple contributions.
Subcomponent analysis considers the relative myogenic (resistance area product, RAP) and metabolic (critical closing pressure (CrCP)) contributors. The aim of this study was to investigate the changes in subcomponents that occur with cognitive stimulation with the Addenbrooke's Cognitive Examination (ACE-III) in healthy controls.
Healthy volunteers underwent continuous recording of bilateral TCD, heart rate (HR, three-lead ECG), end-tidal CO2 (ETCO2 , capnography), and mean arterial pressure (MAP, Finometer). The study comprised a 5-min baseline recording, followed by all 20 paradigms from the ACE-III.
The cerebral blood flow velocity (CBFv) response was decomposed into the relative contributions (subcomponents); VBP (MAP), VCrCP (CrCP), and VRAP (RAP). Data are presented as peak population normalized mean changes from baseline, and median area under the curve (AUC).
Forty bilateral datasets were obtained (27 female, 37 right hand dominant). VBP increased at task initiation in all paradigms but differed between tasks (range (SD): 4.
HR, but not ETCO2 , also differed significantly (P< 0.
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VCrCP AUC varied significantly within paradigm sections (range SD : 18. All paradigms demonstrated changes in subcomponents with cognitive stimulation, and can be ranked based on their relative presumed metabolic demand. The integrity of NVC requires further investigation in patient populations.
Hepatic autophagy has been shown to be regulated by acute exercise and exercise training. Moreover, high‐fat diet‐induced steatosis has been reported to be associated with impaired hepatic autophagy.
In addition, autophagy has been shown to be regulated by acute exercise and exercise training in a PGC‐1 dependent manner in skeletal muscle. The aim of this study was to test the hypotheses that high‐fat high‐fructose (HFF) diet changes hepatic autophagy and mitophagy, that exercise training can restore this through a PGC‐1 ‐mediated mechanism, and that acute exercise regulates autophagy and mitophagy in the liver.
Liver samples were obtained from liver‐specific PGC‐1 KO mice and their littermate Lox/Lox mice fed a HFF diet or a control diet for 13 weeks. The HFF mice were either exercise trained (ExT) on a treadmill the final 5 weeks or remained sedentary (UT).
In addition, half of each group performed at the end of the intervention an acute 1 h exercise bout. HFF resulted in increased hepatic BNIP3 dimer and Parkin protein, while exercise training increased BNIP3 total protein without affecting the elevated BNIP3 dimer protein.
In addition, exercise training reversed a HFF‐induced increase in hepatic LC3II/LC3I protein ratio, as well as a decreased PGC‐1 mRNA level. Acute exercise increased hepatic PGC‐1 mRNA in HFF UT mice only.
In conclusion, this indicates that exercise training in part reverses a HFF‐induced increase in hepatic autophagy and capacity for mitophagy in a PGC‐1 ‐independent manner. Moreover, HFF may blunt acute exercise‐induced regulation of hepatic autophagy.
Exercise training in part reverses diet‐induced increases of hepatic autophagy and capacity for mitophagy in a PGC‐1 independent manner. Moreover, HFF may blunt acute exercise‐induced regulation of hepatic autophagy.
Cardiorespiratory fitness (CRF) inversely predicts cardiovascular (CV) mortality and CRF is impaired in people with type 2 diabetes (T2D). Aerobic exercise training (ET) improves CRF and is associated with decreased risk of premature death in healthy and diseased populations.
Understanding the mechanisms contributing to ET adaptation may identify targets for reducing CV mortality of relevance to people with T2D. The antihyperglycemic hormone glucagon‐like peptide‐1 (GLP‐1) influences many of the same pathways as exercise and may contribute to CV adaptation to ET.
We hypothesized that GLP‐1 is necessary for adaptation to ET. Twelve‐week‐old male Wistar rats were randomized (n = 8–12/group) to receive PBS or GLP‐1 receptor antagonist (exendin 9‐39 (Ex(9‐39)) via osmotic pump for 4 weeks ± ET.
Ex(9‐39) treatment blunted CRF in both sedentary and ET rats (P< 0. Ex(9‐39) attenuated acetylcholine‐mediated vasodilation, while this response was maintained with Ex(9‐39)+ET (P = 0. Aortic stiffness was greater with Ex(9‐39) (P = 0. 057) and was made worse when Ex(9‐39) was combined with ET (P = 0.
Ex vivo aortic vasoconstriction with potassium and phenylephrine was lower with Ex(9‐39) (P< 0.
Carotid strain improved with PBS + ET but did not change in the Ex(9‐39) rats with ET (P< 0.
Left ventricular mitochondrial respiration was elevated with Ex(9‐39) (P< 0.
GLP‐1 receptor antagonism impairs CRF with and without ET, attenuates the vascular adaptation to ET, and elevates cardiac mitochondrial respiration.
These data suggest that GLP‐1 is integral to the adaptive vascular response to ET. GLP‐1 receptor antagonism impairs exercise capacity, attenuates the vascular adaptation to exercise training, and elevates cardiac mitochondrial respiration.
These data suggest that GLP‐1 is integral to the adaptive vascular response to exercise training. Neurons and glia exhibit metabolic imbalances in hypertensive animal models, and loss of metabolic homeostasis can lead to neuroinflammation and oxidative stress.
The objective of this study was to determine the effects of the microbial metabolite butyrate on mitochondrial bioenergetics and inflammatory markers in mixed brainstem and hypothalamic primary cultures of astrocytes between normotensive (Sprague-Dawley, S-D) and spontaneously hypertensive (SHR) rats. Bioenergetics of mitochondria in astrocytes from normotensive S-D rats were modified with butyrate, but this was not the case in astrocytes derived from SHR, suggesting aberrant mitochondrial function.
Transcripts related to oxidative stress, butyrate transporters, butyrate metabolism, and neuroinflammation were quantified in astrocyte cultures treated with butyrate at 0, 200, 600, and 1000 mol/L. Butyrate decreased catalase and monocarboxylate transporter 1 mRNA in astrocytes of S-D rats but not in the SHR.
Moreover, while butyrate did not directly regulate the expression of 3-hydroxybutyrate dehydrogenase 1 and 2 in astrocytes of either strain, the expression levels for these transcripts in untreated cultures were lower in the SHR compared to S-D. We observed higher levels of specific inflammatory cytokines in astrocytes of SHR, and treatment with butyrate decreased expression of Ccl2 and Tlr4 in SHR astrocytes only.
Conversely, butyrate treatment increased expression of tumor necrosis factor in astrocytes from SHR but not from the S-D rats. This study improves our understanding of the role of microbial metabolites in regulating astrocyte function, and provides support that butyrate differentially regulates both the bioenergetics and transcripts related to neuroinflammation in astrocytes from SHR versus S-D rats.
Intramuscular factors that modulate fat-free mass (FFM) loss in lowlanders exposed to energy deficit during high-altitude (HA) sojourns remain unclear. Muscle inflammation may contribute to FFM loss at HA by inducing atrophy and inhibiting myogenesis via the tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) and its receptor, fibroblast growth factor-inducible protein 14 (Fn14).
To explore whether muscle inflammation modulates FFM loss reportedly developing during HA sojourns, muscle inflammation, myogenesis, and proteolysis were assessed in 16 men at sea level (SL) and following 21 days of energy deficit (-1862 ± 525 kcal/days) at high altitude (HA, 4300 m). Total body mass (TBM), FFM, and fat mass (FM) were assessed using DEXA.
Gene expression and proteolytic enzymatic activities were assessed in muscle samples collected at rest at SL and HA. 05); 43 ± 30% and 57 ± 30% of the TBM lost was FFM and FM, respectively. Fn14, TWEAK, TNF alpha-receptor (TNF -R), TNF , MYOGENIN, and paired box protein-7 (PAX7) were upregulated (P< 0.
Stepwise linear regression identified that Fn14 explained the highest percentage of variance in FFM loss (r2 = 0.
Dichotomization of volunteers into HIGH and LOW Fn14 gene expression indicated HIGH lost less FFM and more FM (28 ± 28% and 72 ± 28%, respectively) as a proportion of TBM loss than LOW (58 ± 26% and 42 ± 26%; P< 0. MYOGENIN gene expression was also greater for HIGH versus LOW (P< 0. These data suggest that heightened Fn14 gene expression is not catabolic and may protect FFM during HA sojourns. Chronic kidney disease (CKD) and uremia increase the risk of heart disease and sudden cardiac death.
Coronary artery disease can only partly account for this. The remaining mechanistic links between CKD and sudden death are elusive, but may involve cardiac arrhythmias.
For the present study, we hypothesized that a thorough electrophysiological study in mice with CKD would provide us valuable information that could aid in the identification of additional underlying causes of sudden cardiac death in patients with kidney disease. Partial (5/6) nephrectomy (NX) in mice induced mild CKD: plasma urea in NX was 24 ± 1 mmol/L (n = 23) versus 12 ± 1 mmol/L (n = 22) in sham-operated control mice (P< 0.
Echocardiography did not identify structural or mechanical remodeling in NX mice.
Baseline ECG parameters were comparable in conscious NX and control mice; however, the normal 24-h diurnal rhythm in QRS duration was lost in NX mice. Moreover, -adrenergic stimulation (isoprenaline, 200 g/kg intraperitoneally) prolonged QRS duration in conscious NX mice (from 12 ± 1 to 15 ± 2 msec, P< 0.
05), but not in sham-operated controls (from 13 ± 1 to 13 ± 2 msec, P >0. No spontaneous arrhythmias were observed in conscious NX mice, and intracardiac pacing in anesthetized mice showed a comparable arrhythmia vulnerability in NX and sham-operated mice. Isoprenaline (2 mg/kg intraperitoneally) changed the duration of the QRS complex from 11.
Ex vivo measurements of cardiac ventricular conduction velocity were comparable in NX and sham mice. Transcriptional activity of Scn5a, Gja1 and several profibrotic genes was similar in NX and sham mice.
We conclude that proper kidney function is necessary to maintain diurnal variation in QRS duration and that sympathetic regulation of the QRS duration is altered in kidney disease. Active reabsorption of magnesium (Mg2+ ) in the distal convoluted tubule (DCT) of the kidney is crucial for maintaining Mg2+ homeostasis.
Impaired activity of the Na+ -Cl- -cotransporter (NCC) has been associated with hypermagnesiuria and hypomagnesemia, while increased activity of NCC, as observed in patients with Gordon syndrome, is not associated with alterations in Mg2+ balance. To further elucidate the possible interrelationship between NCC activity and renal Mg2+ handling, plasma Mg2+ levels and urinary excretion of sodium (Na+ ) and Mg2+ were measured in a mouse model of Gordon syndrome.
In this model, DCT1-specific expression of a constitutively active mutant form of the NCC-phosphorylating kinase, SPAK (CA-SPAK), increases NCC activity and hydrochlorothiazide (HCTZ)-sensitive Na+ reabsorption. These mice were normomagnesemic and HCTZ administration comparably reduced plasma Mg2+ levels in CA-SPAK mice and control littermates.
As inferred by the initial response to HCTZ, CA-SPAK mice exhibited greater NCC-dependent Na+ reabsorption together with decreased Mg2+ reabsorption, compared to controls. Following prolonged HCTZ administration (4 days), CA-SPAK mice exhibited higher urinary Mg2+ excretion, while urinary Na+ excretion decreased to levels observed in control animals.
Surprisingly, CA-SPAK mice had unaltered renal expression of Trpm6, encoding the Mg2+ -permeable channel TRPM6, or other magnesiotropic genes. In conclusion, CA-SPAK mice exhibit normomagnesemia, despite increased NCC activity and Na+ reabsorption.
Thus, Mg2+ reabsorption is not coupled to increased thiazide-sensitive Na+ reabsorption, suggesting a similar process explains normomagnesemia in Gordon syndrome. Further research is required to unravel the molecular underpinnings of this phenomenon and the more pronounced Mg2+ excretion after prolonged HCTZ administration.
Skeletal muscle autophagy is suppressed by insulin, but it is not clear if such suppression is altered with insulin resistance. We investigated if the inhibitory action of insulin on autophagy remains intact despite insulin resistance to glucose metabolism.
C57BL/6J mice consumed either a low-fat (10% fat) diet as control or high-fat (60% fat) diet for 12 weeks to induce insulin resistance. Following a 5-hour fast, mice underwent either hyperinsulinemic-euglycemic, hyperinsulinemic-hyperglycemic, or saline infusion to test the effect of insulin on autophagy markers in the quadriceps muscle (n = 8-10 per diet and clamp condition).
Mice were anesthetized by sodium pentobarbital for tissue collection after 2 h of infusion. Despite the high-fat group having lower insulin-stimulated glucose uptake, both low-fat and high-fat groups had similar autophagosome abundance during hyperinsulinemic conditions.
The lipidation of microtubule-associated proteins 1A/1B light chain 3B (LC3II/LC3I) was decreased in hyperinsulinemia versus saline control (P< 0. 01) in low-fat (-54%) and high-fat groups (-47%), demonstrating similar suppression of autophagy between diet groups.
Mitochondrial-associated LC3II was greater in the high-fat compared to the low-fat group (P = 0. 045) across clamp conditions, suggesting a greater localization of autophagosomes with mitochondria.
L6 myotubes were treated with insulin and rapamycin to determine the role of mechanistic target of rapamycin complex-1 (mTORC1) in insulin-mediated suppression of autophagy. Inhibition of mTORC1 blunted the decline of LC3II/LC3I with insulin by 40%, suggesting mTORC1 partially mediates the insulin action to suppress autophagy.
Collectively, autophagy remained responsive to the suppressive effects of insulin in otherwise insulin-resistant and obese mice. Prediabetes is associated with impaired contraction‐evoked dilation of skeletal muscle arterioles, which may be due to increased sympathetic activity accompanying this early stage of diabetes disease.
Herein, we sought to determine whether blunted contraction‐evoked vasodilation resulted from enhanced sympathetic neuropeptide Y1 receptor (Y1R) and alpha‐1 adrenergic receptor ( 1R) activation. Using intravital video microscopy, second‐, third‐, and fourth‐order (2A, 3A, and 4A) arteriolar diameters were measured before and following electrical field stimulation of the gluteus maximus muscle (GM) in prediabetic (PD, Pound Mouse) and control (CTRL, c57bl6, CTRL) mice.
Baseline diameter was similar between groups; however, single tetanic contraction (100 Hz; 400 and 800 msec) and sustained rhythmic contraction (2 and 8 Hz, 30 sec) evoked rapid onset vasodilation and steady‐state vasodilatory responses that were blunted by 50% or greater in PD versus CTRL. Following Y1R and 1R blockade with sympathetic antagonists BIBP3226 and prazosin, contraction‐evoked arteriolar dilation in PD was restored to levels observed in CTRL.
Furthermore, arteriolar vasoconstrictor responses to NPY (10−13–10−8 mol/L) and PE (10−9–10−5 mol/L) were greater in PD versus CTRL at higher concentrations, especially at 3A and 4A. These findings suggest that contraction‐evoked vasodilation in PD is blunted by Y1R and 1R receptor activation throughout skeletal muscle arteriolar networks.
Elevated activation of peptidergic and adrenergic receptors blunts arteriolar responses to muscle contraction in a murine model of prediabetes. This study assesses positional changes in cardiac power output and stroke work compared with classic hemodynamic variables, measured before and after elective coronary artery bypass graft surgery.
The hypothesis was that cardiac power output was altered in relation to cardiac stunning. The study is a retrospective analysis of data from two previous studies performed in a tertiary care university hospital.
Thirty-six patients scheduled for elective coronary artery bypass graft surgery, with relatively preserved left ventricular function, were included. A pulmonary artery catheter and a radial artery catheter were placed preoperatively.
Cardiac power output and stroke work were calculated through thermodilution both supine and standing prior to induction of anesthesia and again day one postoperatively. Virtually all systemic hemodynamic parameters changed significantly from pre- to postoperatively, and from supine to standing.
3) W both pre- and postoperatively and from supine to standing on both days.
Stroke work fell from pre- to postoperatively from 1. 001), there was a significant fall in stroke work with positional change preoperatively from 1.
Cardiac power output was the only systemic hemodynamic variable which remained unaltered during all changes.
Stroke work appears to be a more sensitive marker for temporary cardiovascular dysfunction than cardiac power output. Further studies should explore the relationship between stroke work and cardiac performance and whether cardiac power output is an autoregulated intrinsic physiological parameter.
Curcumin, a naturally occurring plant polyphenolic compound, may have beneficial effects in nonalcoholic steatohepatitis (NASH) development. We examined whether curcumin supplementation could be used in both prevention and treatment of NASH with fibrosis.
Female Wistar rats were provided ad libitum access to a "western diet" (WD) high in fat (43% kcal), sucrose (29% kcal), and cholesterol (2% w/v), as well as 15% fructose drinking water. 5 mL/kg) were also administered at weeks 1, 2, 4, and 6 to accelerate development of a NASH with fibrosis phenotype. Rats were randomized to four groups (n = 9-12/group) and fed ad libitum: (1) WD for 8-weeks (8WD), (2) WD enriched with curcumin for 8-weeks (8WD+C; 0.
2% curcumin, BCM-95, DolCas Biotech) to assess prevention, (3) WD for 12-weeks (12WD), (4) WD for 8-weeks followed by 4-weeks WD+C (12WD+C) to assess treatment. 05) histological liver inflammation, molecular markers of fibrosis (Col1a1 mRNA) and a serum marker of liver injury (AST).
05) hepatocellular inflammation, steatosis, NAFLD Activity Scores, and serum markers of liver injury (AST, ALP). Moreover, curcumin treatment also increased hepatic pACC/ACC, ApoB100, and SOD1 protein, and decreased hepatic FGF-21 levels; whereas, curcumin prevention increased hepatic glutathione levels.
Both curcumin prevention and treatment reduced molecular markers of hepatic fibrosis (Col1a1 mRNA) and inflammation (TNF- , SPP1 mRNA). Curcumin supplementation beneficially altered the NASH phenotype in female Wistar rats, particularly the reversal of hepatocellular inflammation.
Obese individuals exhibit a diminished muscle protein synthesis response to nutrient stimulation when compared with their lean counterparts. However, the effect of obesity on exercise-stimulated muscle protein synthesis remains unknown.
2 kg/m2 ) physically active young adults participated in a study that determined muscle protein synthesis and intracellular signaling at rest and following an acute bout of resistance exercise. Mixed muscle protein synthesis was determined by combining stable isotope tracer ( 13 C6 phenylalanine) infusion with serial biopsies of the vastus lateralis.
A unilateral leg resistance exercise model was adopted so that resting and postexercise measurements of muscle protein synthesis could be obtained simultaneously. Obesity was associated with higher basal levels of serum insulin (P< 0.
01), as well as increased insulin resistance determined by HOMA-IR (P< 0.
However, resting and postexercise rates of muscle protein synthesis were not significantly different between lean and obese participants (P = 0.
Furthermore, resistance exercise stimulated muscle protein synthesis (~50% increase) in both groups (P< 0.
001), with no difference between lean and obese (P = 0. Temporal increases in the phosphorylation of intracellular signaling proteins (AKT/4EBP1/p70S6K) were observed within the exercised leg (P< 0. These findings suggest a normal anabolic response to muscle loading in obese young adults. Connections between the vestibular system and the basal ganglia have been postulated since the early 20th century.
However, the results of electrophysiological studies investigating neuronal responses to electrical stimulation of the vestibular system have been inconsistent. The aim of this study was to investigate the effects of electrical stimulation of the vestibular labyrinth on single neuron activity and c‐Fos expression in the rat striatum.
We used electrical stimulation of the vestibular labyrinth (various intensities delivered to the round window) to examine the electrophysiological response of striatal neurons and c‐Fos expression. From 507 single neurons recorded (n = 20 rats), no vestibular‐responsive neuron was found at 1× and 2× the nystagmus threshold; however, 6 neurons were found at 3× the threshold.
These neurons were found bilaterally, with a response latency of ~50 msec from the end of the stimulus. For the c‐Fos study, the number of neurons expressing c‐Fos was quantified using stereological methods.
Stimulation at 2× the threshold for nystagmus (n = 5 rats) resulted in a significant decrease in the number of neurons expressing c‐Fos in the bilateral striatum compared to both the sham control group (n = 5) and the lower stimulus intensity group (n = 5) (P ≤ 0. The results of this study demonstrate that: (1) some single striatal neurons respond to electrical vestibular stimulation, however, these responses are circumscribed and infrequent; (2) electrical stimulation of the vestibular labyrinth results in a decrease in the number of striatal neurons expressing c‐Fos, in a current‐dependent manner. This article explores the relationship between electrical stimulation of the rat peripheral vestibular system and the striatum, using electrophysiological and immunohistochemical methods.
The striatum consists of the dorsal (caudate/putamen) and the ventral (nucleus accumbens) regions. The nucleus accumbens is further divided into a core and shell.
Both the dorsal and ventral striatum contain populations of spiny projection neurons, which make up 95% of the neurons within the striatum. SPNs are canonically categorized into those that express the D1‐type dopamine receptor (D1 SPNs) and those that express the D2‐type dopamine receptor (D2 SPNs).
D1 and D2 SPNs differ with respect to both synaptic inputs and projection targets. In the dorsal striatum, it is well established that these populations of SPNs differ in terms of their electrophysiological and morphological properties.
However, there remains a gap in our knowledge of the electrophysiological properties of SPNs in the nucleus accumbens core. To evaluate the differential properties of these SPNs, we performed whole‐cell recordings from D1 and D2 SPNs in BAC transgenic mice in which D1 SPNs fluoresce red and D2 SPNs fluoresce green.
The two SPN subtypes did not differ in terms of their time constant, capacitance, resting membrane potential, or tonic current. However, D2 SPNs displayed heightened inhibitory postsynaptic current (IPSC) and miniature excitatory PSC frequency as compared with D1 SPNs.
Furthermore, D2 SPNs displayed decreased rheobase, increased excitability as measured by firing rates to depolarizing current injections, increased inward rectification, increased input resistance, and decreased dendritic complexity compared to D1 SPNs. Our results demonstrate a dichotomy in the electrophysiological properties of D1 and D2 SPNs in the nucleus accumbens core, which contributes to our knowledge of ventral striatal circuitry.
D1 and D2 spiny projection neurons of the nucleus accumbens core display differential electrophysiological and anatomical properties. Previous studies suggest that the loss of estrogens increase one's risk for type 2 diabetes (T2D), and combining the loss of estrogens with a high‐fat diet (HFD) poses an even greater risk for T2D.
The extent to which exercise can ameliorate the deleterious effects of estrogen loss combined with a HFD and the molecular mechanisms accounting for the whole body changes is currently unknown. Therefore, we fed female Wistar rats a standard diet or a HFD for 10 weeks.
The rats fed the HFD were either ovariectomized (OVX) or their ovaries remained intact. A subset of the HFD/OVX rats also underwent exercise training on a motor‐driven treadmill.
Exercise significantly reduced the total body weight gain, periuterine white adipose tissue (WAT) weight, hyperglycemia, and hyperinsulinemia. Additionally, the ability to store fat, as measured by lipoprotein lipase (LPL) in the WAT, was increased in the HFD/OVX group; however, exercise reduced the LPL levels.
Furthermore, the combination of the HFD with OVX decreased the WAT citrate synthase protein level, which was increased with exercise. These data suggest that even during the combined HFD/OVX physiological state, exercise can decrease several risk factors associated with T2D, decrease fat storage, and increase fuel utilization.
Exercise significantly reduced the total body weight gain, periuterine white adipose tissue (WAT) weight, hyperglycemia, and hyperinsulinemia. Additionally, the ability to store fat, as measured by lipoprotein lipase (LPL) in the WAT, was increased in the HFD/OVX group; however, exercise reduced the LPL levels.
Furthermore, the combination of the HFD with OVX decreased the WAT citrate synthase protein level, which was increased with exercise. Intestinal epithelial cell derived alkaline phosphatase (IAP) dephosphorylates/detoxifies bacterial endotoxin lipopolysaccharide (LPS) in the gut lumen.
We have earlier demonstrated that consumption of high-fat high-cholesterol containing western type-diet (WD) significantly reduces IAP activity, increases intestinal permeability leading to increased plasma levels of LPS and glucose intolerance. Furthermore, oral supplementation with curcumin that increased IAP activity improved intestinal barrier function as well as glucose tolerance.
To directly test the hypothesis that targeted increase in IAP would protect against WD-induced metabolic consequences, we developed intestine-specific IAP transgenic mice where expression of human chimeric IAP is under the control of intestine-specific villin promoter. This chimeric human IAP contains domains from human IAP and human placental alkaline phosphatase, has a higher turnover number, narrower substrate specificity, and selectivity for bacterial LPS.
Chimeric IAP was specifically and uniformly overexpressed in these IAP transgenic (IAPTg) mice along the entire length of the intestine. While IAP activity reduced from proximal P1 segment to distal P9 segment in wild-type (WT) mice, this activity was maintained in the IAPTg mice.
Dietary challenge with WD impaired glucose tolerance in WT mice and this intolerance was attenuated in IAPTg mice. Significant decrease in fecal zonulin, a marker for intestinal barrier dysfunction, in WD fed IAPTg mice and a corresponding decrease in translocation of orally administered nonabsorbable 4 kDa FITC dextran to plasma suggests that IAP overexpression improves intestinal barrier function.
Thus, targeted increase in IAP activity represents a novel strategy to improve WD-induced intestinal barrier dysfunction and glucose intolerance. The intestinal epithelium is continuously regenerated by cell renewal of intestinal epithelial stem cells (IESCs) located in the intestinal crypts.
Obesity affects this process and results in changes in the size and cellular make-up of the tissue, but it remains unknown if there are sex differences in obesity-induced alterations in IESC proliferation and differentiation. We fed male and female mice a 60% high-fat diet (HFD) or a 10% low-fat diet (LFD) for 3 months and investigated the differences in (1) the expression of markers of different intestinal epithelial cell types in vivo, and (2) lasting effects on IESC growth in vitro.
We found that the growth of IESCs in vitro were enhanced in females compared with males. HFD induced similar in vivo changes and in vitro early growth of IESCs in males and females.
The IESCs isolated and grown in vitro from females, though, showed an enhanced growth that was independent of obesity. To determine whether this effect was driven by sex steroid hormones, we used primary intestinal crypts isolated from male and female mice and investigated the differences in (1) the expression of steroid hormone receptors, and (2) cell proliferation in response to steroid hormones.
We found that estrogen receptor was expressed in crypts from both sexes, but estrogen had no effect on proliferation in either sex. These results suggest that obesity similarly effects IESCs in males and females, but IESCs in females have greater proliferation ability than males, but this is not driven by a direct effect of sex steroid hormones on IESCs or other crypt cells that provide essential niche support for IESCs.
Critical power is a fundamental parameter defining high-intensity exercise tolerance, and is related to the phase II time constant of pulmonary oxygen uptake kinetics ( V˙O2). Whether this relationship is causative is presently unclear.
This study determined the impact of raised baseline work rate, which increases V˙O2, on critical power during upright cycle exercise. Critical power was determined via four constant-power exercise tests to exhaustion in two conditions: (1) with exercise initiated from an unloaded cycling baseline (U→S), and (2) with exercise initiated from a baseline work rate of 90% of the gas exchange threshold (M→S).
During these exercise transitions, V˙O2 and the time constant of muscle deoxyhemoglobin kinetics ( HHb + Mb ) (the latter via near-infrared spectroscopy) were determined. In M→S, critical power was lower (M→S = 203 ± 44 W vs.
Additionally, HHb + Mb was greater in M→S compared with U→S (M→S = 28 ± 7 sec vs. The increase in V˙O2 and concomitant reduction in critical power in M→S compared with U→S suggests a causal relationship between these two parameters.
However, that HHb + Mb was greater in M→S exculpates reduced oxygen availability as being a confounding factor. These data therefore provide the first experimental evidence that V˙O2 is an independent determinant of critical power.
Keywords critical power, exercise tolerance, oxygen uptake kinetics, power-duration relationship, muscle deoxyhemoglobin kinetics, work-to-work exercise. A high‐fat diet can induce inflammation and metabolic diseases such as diabetes and atherosclerosis.
The receptor for advanced glycation endproducts (RAGE) plays a critical role in metabolic disease pathophysiology and the soluble form of the receptor (sRAGE) can mitigate these effects. However, little is known about RAGE in the postprandial condition and the effect of exercise in this context.
Thus, we aimed to determine the effects of a single high‐fat meal (HFM) with and without prior exercise on peripheral blood mononuclear cell (PBMC) RAGE biology. Healthy males (n = 12) consumed a HFM on two occasions, one without prior exercise and one 16–18 hours following acute aerobic exercise.
Total soluble RAGE (sRAGE) and endogenous secretory RAGE (esRAGE) were determined via ELISA and cleaved RAGE (cRAGE) was calculated as the difference between the two. Isolated PBMCs were analyzed for RAGE, ADAM10, TLR4, and MyD88 protein expression and ADAM10 activity.
Whereas, the HFM increased PBMC RAGE protein expression by 10.
01), there was no meal effect on PBMC TLR4, MYD88, or ADAM10 protein expression, nor ADAM10 activity.
There was also no exercise effect on any experimental outcomes. These findings suggest that PBMC RAGE and soluble RAGE may be important in the postprandial response to a HFM, and that prior aerobic exercise does not alter these processes in young healthy adult males.
The mechanisms by which a HFM induces RAGE expression and reduces circulating soluble RAGE isoforms requires further study. Receptor for advanced glycation endproducts expression differs among circulating immune cell populations.
Continuous Ca2+ influx is essential to maintain intracellular Ca2+ homeostasis and its dysregulation leads to a variety of cellular dysfunctions. In this study, we explored the functional roles of spontaneous Ca2+ influx for the proliferation and differentiation of a human erythromyeloid leukemia cell line K562.
mRNA/protein expressions were assessed by the real-time RT-PCR, western blotting, and immunocytochemical staining. Intracellular Ca2+ concentration ( Ca2+ i ) and ionic currents were measured by fluorescent imaging and patch clamping techniques, respectively.
Cell counting/viability and colorimetric assays were applied to assess proliferation rate and hemoglobin synthesis, respectively. Elimination of extracellular Ca2+ decreased basal Ca2+ i in proliferating K562 cells.
Cation channel blockers such as SK&F96365, 2-APB, Gd3+ , and FTY720 dose dependently decreased basal Ca2+ i . A spontaneously active inward current (Ispont ) contributive to basal Ca2+ i was identified by the nystatin-perforated whole-cell recording.
Ispont permeated Ca2+ comparably to Na+ , and was greatly eliminated by siRNA targeting TRPM7, a melastatin member of the transient receptor potential (TRP) superfamily. Consistent with these findings, TRPM7 immune reactivity was detected by western blotting, and immunofluorescence representing TRPM7 was found localized to the K562 cell membrane.
Strikingly, all these procedures, that is, Ca2+ removal, TRPM7 blockers and siRNA-mediated TRPM7 knockdown significantly retarded the growth and suppressed hemin-induced -globin and hemoglobin syntheses in K562 cells, respectively, both of which appeared associated with the inhibition of ERK activation. These results collectively suggest that spontaneous Ca2+ influx through constitutively active TRPM7 channels may critically regulate both proliferative and erythroid differentiation potentials of K562 cells.
The diaphragm muscle (DIAm) is the primary inspiratory muscle in mammals and is active during ventilatory behaviors, but it is also involved in higher-force behaviors such as those necessary for clearing the airway. Our laboratory has previously reported DIAm sarcopenia in rats and mice characterized by DIAm atrophy and a reduction in maximum specific force at 24 months of age.
In Fischer 344 rats, these studies were limited to male animals, although in other studies, we noted a more rapid increase in body mass from 6 to 24 months of age in females (~140%) compared to males (~110%). This difference in body weight gain suggests a possible sex difference in the manifestation of sarcopenia.
In mice, we previously measured transdiaphragmatic pressure (Pdi) to evaluate in vivo DIAm force generation across a range of motor behaviors, but found no evidence of sex-related differences. The purpose of this study in Fischer 344 rats was to evaluate if there are sex-related differences in DIAm sarcopenia, and if such differences translate to a functional impact on Pdi generation across motor behaviors and maximal Pdi (Pdimax ) elicited by bilateral phrenic nerve stimulation.
In both males and females, DIAm sarcopenia was apparent in 24-month-old rats with a ~30% reduction in both maximum specific force and the cross-sectional area of type IIx and/or IIb fibers. Importantly, in both males and females, Pdi generated during ventilatory behaviors was unimpaired by sarcopenia, even during more forceful ventilatory efforts induced via airway occlusion.
Although ventilatory behaviors were preserved with aging, there was a ~20% reduction in Pdimax , which likely impairs the ability of the DIAm to generate higher-force expulsive airway clearance behaviors necessary to maintain airway patency. Artificial sweeteners are extensively used by the food industry to replace sugar in food and beverages and are widely considered to be a healthy alternative.
However, recent data suggest that artificial sweeteners may impact intestinal glucose absorption and that they might lead to glucose intolerance. Moreover, chronic consumption of artificial sweeteners has also been linked to detrimental changes in renal function.
Using an in vivo approach, our study aimed to determine if short-term infusion of the artificial sweetener saccharin can alter renal function and renal glucose absorption. We show that saccharin infusion does not induce any major change in GFR or urine flow rate at either the whole kidney or single nephron level, suggesting that any reported change in renal function with artificial sweeteners must depend on chronic consumption.
As expected for a nondiabetic animal, glucose excretion was low; however, saccharin infusion caused a small, but significant, decrease in fractional glucose excretion. In contrast to the whole kidney data, our micropuncture results did not show any significant difference in fractional glucose reabsorption in either the proximal or distal tubules, indicating that saccharin does not influence renal glucose handling in vivo under euglycemic conditions.
In keeping with this finding, protein levels of the renal glucose transporters SGLT1 and SGLT2 were also unchanged. In addition, saccharin infusion in rats undergoing a glucose tolerance test failed to induce a robust change in renal glucose excretion or renal glucose transporter expression.
In conclusion, our results demonstrate that saccharin does not induce acute physiologically relevant changes in renal function or renal glucose handling. Interleukin 6 (IL‐6) is a cytokine secreted from skeletal muscle in response to exercise which, based on animal and cell studies, has been suggested to contribute to glucose metabolism by increasing secretion of the incretin hormone glucagon‐like peptide‐1 (GLP‐1) and affecting secretion of insulin and glucagon from the pancreatic islets.
We investigated the effect of IL‐6 on GLP‐1 secretion in GLP‐1 producing cells (GLUTag) and using the perfused mouse small intestine (harboring GLP‐1 producing cells). Furthermore, the direct effect of IL‐6 on insulin and glucagon secretion was studied using isolated perfused mouse pancreas.
Incubating GLUTag cells with 1000 ng/mL of IL‐6 for 2 h did not significantly increase secretion of GLP‐1 whereas 10 mmol/L glucose (positive control) did. Similarly, IL‐6 (100 ng/mL) had no effect on GLP‐1 secretion from perfused mouse small intestine whereas bombesin (positive control) increased secretion.
Finally, administering IL‐6 (100 ng/mL) to perfused mouse pancreases did not significantly increase insulin or glucagon secretion regardless of perfusate glucose levels (3. Acute effects of IL‐6 therefore do not seem to include a stimulatory effect on GLP‐1 secretion in mice.
Interleukin 6 (IL‐6) is secreted during exercise and has been suggested to improve glucose homeostasis by stimulating secretion of glucagon‐like peptide‐1 (GLP‐1). Here, we show that IL‐6 does not acutely stimulates the secretion of GLP‐1 in mice.
The benefical effect of IL‐6 on blood glucose therefore seems to be independent of GLP‐1. Recent findings of podocyte shedding/podocyturia highlight the central significance of podocyte injury in preeclampsia, a hypertensive disorder unique to human pregnancy.
To test the hypothesis that oxidative stress contributes to kidney podocyte injury in preeclampsia, we specifically examined expression and distribution of antioxidant CuZn-SOD with nephrin and podoplanin in shed podocytes from women with preeclampsia. We found that CuZn-SOD was localized at the front/outreach region of nephrin at the cell periphery (foot process areas) in control podocytes and expression of CuZn-SOD, nephrin, and podoplanin were all dislocated or lost in shed podocytes from preeclamptic patients. We further tested oxidative stress-induced nephrin shedding in podocytes, in which AB 8/13 podocytes were cultured under lowered oxygen condition (2%O2 ) or treated with hypoxic mimicking agent cobalt chloride.
Our results showed that reduced nephrin and podoplanin expression were associated with downregulation of CuZn-SOD expression in podocytes when cells were cultured under lowered oxygen or hypoxic conditions. Nephrin shed in urinary specimen from preeclamptic women was also determined by immunoprecipitation/immunoblotting.
The molecular sizes of nephrin that corresponded to that were lost when cells were cultured under hypoxic conditions. We concluded that increased oxidative stress plays a significant role in inducing podocyte protein shedding in preeclampsia.
This study combines two well‐known vascular research models, hyperoxia and hind limb ischemia, aiming to better characterize capacities of the hyperoxia challenge. We studied two groups of C57/BL6 male mice, a control (C) and a hind limb ischemia (HLI) group.
Perfusion from both limbs was recorded in all animals by laser Doppler techniques under an oxygen (O2) saturated atmosphere, once for control and, during 35 days for the HLI group. We used a third set of normoxic animals for HLI morphometric control.
The expected variability of responses was higher for the younger animals. In the HLI group, capillary density normalized at Day 21 as expected, but not microcirculatory physiology.
In the operated limb, perfusion decreased dramatically following surgery (Day 4), as a slight reduction in the non‐operated limb was also noted. Consistently, the response to hyperoxia was an increased perfusion in the ischemic limb and decreased perfusion in the contralateral limb.
Only at Day 35, both limbs exhibited similar flows, although noticeably lower than Day 0. These observations help to understand some of the functional variability attributed to the hyperoxia model, by showing (i) differences in the circulation of the limb pairs to readjust a new perfusion set‐point even after ischemia, an original finding implying that (ii) data from both limbs should be recorded when performing distal measurements in vivo.
Our data demonstrate that the new vessels following HLI are not functionally normal, and this also affects the non‐operated limb. These findings confirm the discriminative capacities of the hyperoxia challenge and suggest its potential utility to study other pathologies with vascular impact.
A patent foramen ovale (PFO) is linked to increased risk of decompression illness in divers. One theory is that venous gas emboli crossing the PFO can be minimized by avoiding lifting, straining and Valsalva maneuvers.
Alternatively, we hypothesized that mild increases in external inspiratory and expiratory resistance, similar to that provided by a SCUBA regulator, recruit the PFO. Nine healthy adults with a Valsalva‐proven PFO completed three randomized trials (inspiratory, expiratory, and combined external loading) with six levels of increasing external resistance (2–20 cmH2O/L/sec).
An agitated saline contrast echocardiogram was performed at each level to determine foramen ovale patency. Contrary to our hypothesis, there was no relationship between the number of subjects recruiting their PFO and the level of external resistance.
In fact, at least 50% of participants recruited their PFO during 14 of 18 trials and there was no difference between the combined inspiratory, expiratory, or combined external resistance trials (P >0. We further examined the relationship between PFO recruitment and intrathoracic pressure, estimated from esophageal pressure. Esophageal pressure was not different between participants with and without a recruited PFO.
Intrasubject variability was the most important predictor of PFO patency, suggesting that some individuals are more likely to recruit their PFO in the face of even mild external resistance. Right‐to‐left bubble passage through the PFO occurs in conditions that are physiologically relevant to divers.
Transthoracic echocardiography with mild external breathing resistance may be a tool to identify divers that are at risk of PFO‐related decompression illness. We find that a small increase in external airways resistance recruits the foramen ovale in many individuals.
This is relevant for divers because recruitment of the foramen ovale is linked to decompression illness. Sodium and fluid retention is a hallmark and a therapeutic challenge of the nephrotic syndrome (NS).
Studies support the “overfill” theory of NS with pathophysiological proteolytic activation of the epithelial sodium channel (ENaC) which explains the common observation of suppressed renin –angiotensin system and poor therapeutic response to ACE inhibitors.
Sample lab report - hamilton college
We describe a 38‐year‐old male patient with type1 diabetes who developed severe hypertension (200/140 mmHg), progressive edema (of at least 10 L), and overt proteinuria (18.
5 g/24 h), despite combined administration of five antihypertensive drugs Physiological Reports | Read articles with impact on ResearchGate, the and a high‐protein low carbohydrate (HPLC) diet have been reported to positively and Using intravital video microscopy, second‐, third‐, and fourth‐order (2A, 3A, .
Addition of amiloride (5 mg/day) to treatment resulted in resolution of edema, weight loss of 7 kg, reduction in blood pressure (150/100–125/81 mmHg), increased 24 h urinary sodium excretion (127–165 mmol/day), decreased eGFR (41–29 mL/min), and increased plasma potassium concentration (4. Blocking of ENaC mobilizes nephrotic edema and lowers blood pressure in NS.
However, acute kidney injury and dangerous hyperkalemia is a potential risk if amiloride is added to multiple other antihypertensive medications as ACEi and spironolactone. The findings support that ENaC is active in NS and is a relevant target in adult NS patients.
Amiloride resolves resistant edema and hypertension in a patient with nephrotic syndromeGABAergic inhibition plays a critical role in the regulation of neuronal activity. In the neocortex, inhibitory interneurons that target the dendrites of pyramidal cells influence both electrical and biochemical postsynaptic signaling.
Voltage‐gated ion channels strongly shape dendritic excitability and the integration of excitatory inputs, but their contribution to GABAergic signaling is less well understood. By combining 2‐photon calcium imaging and focal GABA uncaging, we show that voltage‐gated potassium channels normally suppress the GABAergic inhibition of calcium signals evoked by back‐propagating action potentials in dendritic spines and shafts of cortical pyramidal neurons.
Moreover, the voltage‐dependent inactivation of these channels leads to enhancement of dendritic calcium inhibition following somatic spiking. Computational modeling reveals that the enhancement of calcium inhibition involves an increase in action potential depolarization coupled with the nonlinear relationship between membrane voltage and calcium channel activation.
Overall, our findings highlight the interaction between intrinsic and synaptic properties and reveal a novel mechanism for the activity‐dependent regulation of GABAergic inhibition. Here we examine the interaction of dendritic voltage‐gated potassium channels and GABAergic inhibition.
We show that potassium channels normally suppress the inhibition of calcium signals evoked by back‐propagating action potentials in dendritic spines and shafts of cortical pyramidal neurons. Factors associated with plasma levels of adiponectin and leptin were studied in adult subjects without diabetes from Cotonou in Benin (West‐Africa).
Seventy (70) men and 45 women were included in the study. Anthropometric variables were measured and a venous blood sample was drawn from each subject, after an overnight fasting period, for measurement of plasma glucose, insulin, leptin, and adiponectin levels.
HOMA‐IR was determined to assess insulin resistance. Adiponectin and leptin levels were higher in women than in men (with adiponectin 18.
Fasting insulin level and HOMA‐IR were also higher in the females. Hyperleptinemia was observed in 66,96% of subjects and hypoadiponectinemia was present in 44.
In both men and women, leptin correlated with age (r = 0.
No significant correlation was observed for adiponectin levels with these variables. Only in women, adiponectin was inversely correlated with fasting glucose (r = −0.
These data confirm previous descriptions of leptin but suggest that variations in factors determining serum adiponectin levels observed between ethnicities could also been seen between populations from the same ethnicity. This study carried out in west‐African subjects showed that serum leptin and adiponectin levels were significantly higher in women than in men.
Leptin levels were associated with age, body mass index (BMI), waist circumference, Homeostatic model assessment of insulin resistance (HOMA‐IR), and fasting insulin but no significant correlation was observed between adiponectin levels and BMI, waist circumference, and HOMA‐IR. Factors associated with or determining adiponectin levels seem to be ethnicity and even population specific.
To explore mechanisms by which SGLT2 inhibitors protect diabetic hearts from heart failure, we examined the effect of empagliflozin (Empa) on the ultrastructure of cardiomyocytes in the noninfarcted region of the diabetic heart after myocardial infarction (MI). OLETF, a rat model of type 2 diabetes, and its nondiabetic control, LETO, received a sham operation or left coronary artery ligation 12 h before tissue sampling.
Tissues were sampled from the posterior ventricle (i. , the remote noninfarcted region in rats with MI). The number of mitochondria was larger and small mitochondria were more prevalent in OLETF than in LETO.
Fis1 expression level was higher in OLETF than in LETO, while phospho‐Ser637‐Drp1, total Drp1, Mfn1/2, and OPA1 levels were comparable. MI further reduced the size of mitochondria with increased Drp1‐Ser616 phosphorylation in OLETF.
The number of autophagic vacuoles was unchanged after MI in LETO but was decreased in OLETF. Lipid droplets in cardiomyocytes and tissue triglycerides were increased in OLETF.
Empa administration (10 mg/kg per day) reduced blood glucose and triglycerides and paradoxically increased lipid droplets in cardiomyocytes in OLETF. Empa suppressed Fis1 upregulation, increased Bnip3 expression, and prevented reduction in both mitochondrial size and autophagic vacuole number after MI in OLETF.
Together with the results of our parallel study showing upregulation of SOD2 and catalase by Empa, the results indicate that Empa normalizes the size and number of mitochondria in diabetic hearts and that diabetes‐induced excessive reduction in mitochondrial size after MI was prevented by Empa via suppression of ROS and restoration of autophagy. Empagliflozin, an SGLT2 inhibitor, normalized the size and number of mitochondria in diabetic hearts.
In addition, this agent prevented diabetes‐induced excess reduction in mitochondrial size in the noninfarcted myocardium after myocardial infarction. We investigated the effects of regular leucine intake and/or resistance exercise training on skeletal muscle hypertrophy and satellite cell activity after the administration of different doses of leucine.
Ten‐week‐old Sprague–Dawley rats were assigned to six groups (n = 7 per group): a control group (Con), two groups receiving either 10% (0. 675 g/ ) (Leu50) leucine supplementation, and three exercise groups receiving 0% (Ex), 10% (Leu10Ex), and 50% (Leu50Ex) leucine supplementation. The rats performed ladder climbing exercises thrice per week for 8 weeks, and received leucine supplements at the same time daily.
Muscle phenotypes were assessed by immunohistochemistry. MyoD, myogenin, and IGF1 protein levels were determined by western blot.
The Leu50Ex group displayed significantly higher numbers of positive embryonic myosin fibers (0. And exercise training groups increased the cross‐sectional area, the number of satellite cells and protein expression of MyoD, myogenin, and IGF1alpha relative to the Control group (P< 0. However, Only leucine supplementation group did not increase skeletal muscle hypertrophy and satellite cell activity, regardless of the dose (P >0. Leucine intake accompanied by regular exercise training may increase satellite cell activation in skeletal muscles, and improve muscle quality more effectively than continuous leucine ingestion alone. Leucine intake accompanied by regular exercise training may increase satellite cell activation in skeletal muscles, and improve muscle quality more effectively than continuous leucine ingestion alone.
Carbohydrate availability is proposed as a potential regulator of cytokine responses Plant & Cell Physiology (PCP) is an international journal that publishes high quality, original articles reporting significant findings in broad aspects of plant Each author should have participated sufficiently in the work to take public The order of authorship should be a joint decision of the co-authors agreed at the outset..
What is physiological measurement? - the british society for clinical
Thirteen young, healthy, recreationally active males performed two experimental days with endurance exercise in the morning and resistance exercise in the afternoon. Either a carbohydrate (110 g carbohydrate, 52 g protein, 9 g fat; ~750 kcal) or an isocaloric fat meal (20 gr carbohydrate, 52 g protein, 51 g fat) was provided 2 h before resistance exercise.
Blood was taken at baseline and at regular time intervals to measure circulating plasma cytokine levels (e. IL-6, IL-8, IL-10, IL-15, TNF , ANGPTL4, decorin and MCP-1). Plasma glucose and insulin were higher in the postprandial period before the start of the resistance exercise on the carbohydrate condition, while free fatty acids were reduced.
At 2 h postresistance exercise, IL-6 concentrations were higher in the fat condition compared to the carbohydrate condition (P< 0. In addition, in both conditions IL-6 levels were higher at all time points compared with baseline (P< 0. The pattern of increase in plasma IL-8 and IL-10 did not differ significantly between conditions (P >0. There were no differences between conditions on TNF levels and levels remain constant when compared with baseline (P >0. ANGPTL4, IL-15, Decorin and MCP-1 showed no differences between the fat and carbohydrate condition (P >0. The composition of the pre-exercise meal did in general not influence cytokine responses in the postresistance exercise period, except postresistance exercise circulating plasma IL-6 levels being higher in the fat condition compared with carbohydrate. Our findings support the view that pre-exercise carbohydrate availability does not have a major impact on acute responses of circulating plasma cytokines in humans.
Physical inactivity is a leading cause of hypokinetic diseases – obesity, heart disease, diabetes, and certain types of cancers. Increased city walkability, better access to fitness facilities, and remediation of socioeconomic barriers prove successful for limited populations within the confines of stringently controlled environments; however, these strategies fail to reverse the ever‐increasing physical inactivity epidemic on a global scale indicating the existence of other unidentified factors.
These purported biological factors remain critical targets to understand the regulation of this complex phenotype. An estrogenic mechanism that incompletely or slowly adjusts physical activity levels following reintroduction of estrogenic compounds to surgically gonadectomized mice has been postulated to exist.
Currently, this mechanism remains scrutinized due to concerns that elevated estrogen levels induce urinary bladder distension. The distension of the urinary bladder may mechanically disrupt physical activity, masking any physiological effects estrogen has on physical activity.
The purpose of this study was to evaluate the effects of estrogen on physical activity levels while employing dose‐related strategies to alleviate distension in mice. Wheel running data were collected under normal physiological conditions, following removal of endogenous sex steroids via orchidectomy, and during estrogen replacement at various doses (0%, 10%, 50% or 100% estrogen‐containing implants) to induce varying degrees of urinary bladder distension.
006) decreased after orchidectomy, but slowly increased following estrogen replacement. During the study, wheel running did not return to the levels observed in physiologically intact mice.
Significant distension was not observed between estrogen treatment groups indicating that a slow‐responding estrogen effect exists in male mice that prevents wheel running from returning to normal levels immediately following steroid reintroduction. The limited increase in wheel running during estrogen treatment following orchidectomy is not an artifact of induced urinary bladder distension.
Physical activity is an important health‐related behavior that is extensively regulated by robust biological mechanisms. Physical activity regulation has been an active bed of research for over a hundred years, yet surprisingly little is known about the regulatory biology of this complex phenotype.
The present study utilizes an integrative approach to investigate physical activity patterns and concludes that ability and motivation for physical activity are not affected by estrogen‐induced changes to the urinary system. A‐Dysfprmd/GeneJ (BLAJ) mice model human limb‐girdle muscular dystrophy 2B (LGMD2B), which is linked to mutations in the dysferlin (DYSF) gene. We tested the hypothesis that, the calcium ion (Ca2+) channel blocker diltiazem (DTZ), reduces contraction‐induced skeletal muscle damage, in BLAJ mice.
We randomly assigned mice (N = 12; 3–4 month old males) to one of two groups – DTZ (N = 6) or vehicle (VEH, distilled water, N = 6). We conditioned mice with either DTZ or VEH for 1 week, after which, their tibialis anterior (TA) muscles were tested for contractile torque and susceptibility to injury from forced eccentric contractions.
We continued dosing with DTZ or VEH for 3 days following eccentric contractions, and then studied torque recovery and muscle damage. We analyzed contractile torque before eccentric contractions, immediately after eccentric contractions, and at 3 days after eccentric contractions; and counted damaged fibers in the injured and uninjured TA muscles.
We found that DTZ improved contractile torque before and immediately after forced eccentric contractions, but did not reduce delayed‐onset muscle damage that was observed at 3 days after eccentric contractions. Diltiazem improves contractile properties in dysferlin‐deficient BLAJ mouse muscle, but does not reduce contraction‐induced muscle damage.
The importance of myeloid cells in promoting neovascularization has been shown in a number of pathological settings in several organs. However, the specific role of macrophages in promoting systemic angiogenesis during pulmonary ischemia is not fully determined.
Our past work suggested that cells of monocytic lineage contributed to systemic angiogenesis in the lung since clodronate-induced depletion of all macrophages resulted in attenuated neovascularization. Our current goals were to define the population of macrophages important for systemic vessel growth into the lung after the onset of pulmonary ischemia in mice.
Interstitial macrophages (CD64+ MerTK+ CD11b+ ) increased significantly as did the percent of CD45+ Ly6G+ neutrophils 1 day after the induction of left lung ischemia, despite the fact there was limited cell recruitment due to complete obstruction of the left pulmonary artery in this ischemia model. Since both interstitial macrophages and neutrophils express CD11b, we used CD11b+ DTR mice and showed the critical role for these cells since CD11b+ depleted mice showed no systemic angiogenesis 7 days after the onset of ischemia when compared to control mice.
Coculture of mouse aortic endothelial cells with macrophages showed increased proliferation relative to endothelial cells in culture without inflammatory cells, or pulmonary artery endothelial cells. We conclude that CD11b+ leukocytes, trapped within the lung at the onset of ischemia, contribute to growth factor release, and are critical for new blood vessel proliferation.
The sensory innervation of the lung is well known to be innervated by nerve fibers of both vagal and sympathetic origin. Although the vagal afferent innervation of the lung has been well characterized, less is known about physiological effects mediated by spinal sympathetic afferent fibers.
We hypothesized that activation of sympathetic spinal afferent nerve fibers of the lung would result in an excitatory pressor reflex, similar to that previously characterized in the heart. In this study, we evaluated changes in renal sympathetic nerve activity (RSNA) and hemodynamics in response to activation of TRPV1‐sensitive pulmonary spinal sensory fibers by agonist application to the visceral pleura of the lung and by administration into the primary bronchus in anesthetized, bilaterally vagotomized, adult Sprague‐Dawley rats.
Application of bradykinin (BK) to the visceral pleura of the lung produced an increase in mean arterial pressure (MAP), heart rate (HR), and RSNA. This response was significantly greater when BK was applied to the ventral surface of the left lung compared to the dorsal surface.
Conversely, topical application of capsaicin (Cap) onto the visceral pleura of the lung, produced a biphasic reflex change in MAP, coupled with increases in HR and RSNA which was very similar to the hemodynamic response to epicardial application of Cap. This reflex was also evoked in animals with intact pulmonary vagal innervation and when BK was applied to the distal airways of the lung via the left primary bronchus.
In order to further confirm the origin of this reflex, epidural application of a selective afferent neurotoxin (resiniferatoxin, RTX) was used to chronically ablate thoracic TRPV1‐expressing afferent soma at the level of T1–T4 dorsal root ganglia pleura. This treatment abolished all sympatho‐excitatory responses to both cardiac and pulmonary application of BK and Cap in vagotomized rats 9–10 weeks post‐RTX.
These data suggest the presence of an excitatory pulmonary chemosensitive sympathetic afferent reflex. This finding may have important clinical implications in pulmonary conditions inducing sensory nerve activation such as pulmonary inflammation and inhalation of chemical stimuli.
In this study, we provided multiple pieces of evidence showing that topical application of bradykinin (BK) and capsaicin in both ventral and dorsal surfaces of lungs evoked an undocumented potent sympatho‐excitatory response in anesthetized, vagotomized rats. If we ablated the cardiopulmonary spinal afferents at the thoracic T1–T4 DRG regions, the BK and capsaicin‐induced pulmonary spinal activation was abolished.
We believe that this newly identified pulmonary sympatho‐excitatory response will be helpful to further understand the role of pulmonary spinal sensory nerves in modulating cardiovascular function and autonomic activity in healthy and disease states. The sympathetic (SNS) and parasympathetic (PNS) branches of the autonomic nervous system have been implicated in the modulation of the renewal of many tissues, including the intestinal epithelium.
However, it is not known whether these mechanisms are direct, requiring an interaction between autonomic neurotransmitters and receptors on proliferating epithelial cells. To evaluate the existence of a molecular framework for a direct effect of the SNS or PNS on intestinal epithelial renewal, we measured gene expression for the main autonomic neurotransmitter receptors in this tissue.
We separately evaluated intestinal epithelial regions comprised of the stem, progenitor, and mature cells, which allowed us to investigate the distinct contributions of each cell population to this proposed autonomic effect. Notably, we found that the stem cells expressed the receptors for the SNS‐associated alpha2A adrenoreceptor and the PNS‐associated muscarinic acetylcholine receptors (M1 and M3).
In a separate experiment, we found that the application of norepinephrine or acetylcholine decreases the expression of cyclin D1, a gene necessary for cell cycle progression, in intestinal epithelial organoids compared with controls (P< 0. Together, these results provide evidence of a direct mechanism for the autonomic nervous system influence on intestinal epithelial stem cell proliferation. Intestinal epithelial stem cells express sympathetic and parasympathetic neurotransmitter receptors and norepinephrine or acetylcholine decreases the expression of cyclin D, a gene involved in controlling the cell cycle and proliferation.
These data suggest that autonomic nervous system may be involved in the direct control intestinal epithelial stem cell proliferation and tissue renewal, a process necessary to maintain tissue homeostasis. Erythrocytes must maintain a biconcave discoid shape in order to efficiently deliver oxygen (O2 ) molecules and to recycle carbon dioxide (CO2 ) molecules.
The erythrocyte is a small toroidal dielectrophoretic (DEP) electromagnetic field (EMF) driven cell that maintains its zeta potential ( ) with a dielectric constant ( ) between a negatively charged plasma membrane surface and the positively charged adjacent Stern layer. Here, we propose that zeta potential is also driven by both ferroelectric influences (chloride ion) and ferromagnetic influences (serum iron driven).
The Golden Ratio, a function of Phi , offers a geometrical mathematical measure within the distinct and desired curvature of the red blood cell that is governed by this zeta potential and is required for the efficient recycling of CO2 in our bodies. The Bio-Field Array (BFA) shows potential to both drive/fuel the zeta potential and restore the Golden Ratio in human erythrocytes thereby leading to more efficient recycling of CO2 .
Live Blood Analyses and serum CO2 levels from twenty human subjects that participated in immersion therapy sessions with the BFA for 2 weeks (six sessions) were analyzed. Live Blood Analyses (LBA) and serum blood analyses performed before and after the BFA immersion therapy sessions in the BFA pilot study participants showed reversal of erythrocyte rheological alterations (per RBC metric; P = 0.
00000075), a morphological return to the Golden Ratio and a significant decrease in serum CO2 (P = 0. Immersion therapy sessions with the BFA show potential to modulate zeta potential, restore this newly defined Golden Ratio and reduce rheological alterations in human erythrocytes.