AJP: Regulatory, Integrative and Comparative Physiology This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Na+-taurocholate cotransporting polypeptide (NTCP/SLC10A1) ortholog in the marine skate Leucoraja erinacea is not a physiological bile salt transporter
The Na+-dependent taurocholate cotransporting polypeptide (NTCP/SLC10A1) is a hepatocyte-specific solute carrier, which plays an important role in maintaining bile salt homeostasis in mammals. The absence of a hepatic Na+-dependent bile salt transport system in marine skate and rainbow trout raises a question regarding the function of the Slc10a1 gene in these species. Here, we have characterized the Slc10a1 gene in the marine skate, Leucoraja erinacea. The transcript of skate Slc10a1 (skSlc10a1) encodes 319 amino acids and shares 46% identity to human NTCP (hNTCP) with similar topology to mammalian NTCP. SkSlc10a1 mRNA wa...
Source: AJP: Regulatory, Integrative and Comparative Physiology - April 1, 2017 Category: Physiology Authors: Yu, D., Zhang, H., Lionarons, D. A., Boyer, J. L., Cai, S.-Y. Tags: Research Article Source Type: research

Similar pattern of change in VO2 kinetics, vascular function, and tissue oxygen provision following an endurance training stimulus in older and young adults
The purpose of this study was to examine the time course of changes in the oxygen uptake (Vo2) kinetics response subsequent to short-term exercise training (i.e., 24, 48, 72, and 120 h posttraining) and examine the relationship with the time course of changes in microvascular [deoxygenated hemoglobin concentration ([HHb])-to-Vo2 ratio ([HHb])/Vo2)] and macrovascular [flow-mediated dilation (FMD)] O2 delivery to the active tissues/limbs. Seven healthy older [OA; 74 ± 6 (SD) yr] and young men (YA; 25 ± 3 yr) completed three endurance cycling exercise training sessions at 70% Vo2peak. Moderate-intensity exercise...
Source: AJP: Regulatory, Integrative and Comparative Physiology - April 1, 2017 Category: Physiology Authors: McLay, K. M., Murias, J. M., Paterson, D. H. Tags: Research Article Source Type: research

Mechanisms of blood pressure salt sensitivity: new insights from mathematical modeling
Mathematical modeling is an important tool for understanding quantitative relationships among components of complex physiological systems and for testing competing hypotheses. We used HumMod, a large physiological model, to test hypotheses of blood pressure (BP) salt sensitivity. Systemic hemodynamics, renal, and neurohormonal responses to chronic changes in salt intake were examined during normal renal function, fixed low or high plasma angiotensin II (ANG II) levels, bilateral renal artery stenosis, increased renal sympathetic nerve activity (RSNA), and decreased nephron numbers. Simulations were run for 4 wk at salt int...
Source: AJP: Regulatory, Integrative and Comparative Physiology - April 1, 2017 Category: Physiology Authors: Clemmer, J. S., Pruett, W. A., Coleman, T. G., Hall, J. E., Hester, R. L. Tags: Research Article Source Type: research

Regional diaphragm volume displacement is heterogeneous in dogs
Muscle shortening and volume displacement (VD) are critical determinants of the pressure-generating capacity of the diaphragm. The present study was designed to test the hypothesis that diaphragm VD is heterogeneous and that distribution of VD is dependent on regional muscle shortening, posture, and the level of muscle activation. Radioopaque markers were sutured along muscle bundles of the peritoneal surface of the crural, dorsal costal, midcostal, and ventral costal regions of the left hemidiaphragm in four dogs. The markers were followed by biplanar video fluoroscopy during quiet spontaneous breathing, passive inflation...
Source: AJP: Regulatory, Integrative and Comparative Physiology - March 9, 2017 Category: Physiology Authors: Greybeck, B., Lu, R., Ramanujam, A., Adeyeye, M., Wettergreen, M., Wynd, S., Boriek, A. M. Tags: Research Article Source Type: research

Reversible temperature-dependent differences in brown adipose tissue respiration during torpor in a mammalian hibernator
Although seasonal modifications of brown adipose tissue (BAT) in hibernators are well documented, we know little about functional regulation of BAT in different phases of hibernation. In the 13-lined ground squirrel, liver mitochondrial respiration is suppressed by up to 70% during torpor. This suppression is reversed during arousal and interbout euthermia (IBE), and corresponds with patterns of maximal activities of electron transport system (ETS) enzymes. Uncoupling of BAT mitochondria is controlled by free fatty acid release stimulated by sympathetic activation of adipocytes, so we hypothesized that further regulation a...
Source: AJP: Regulatory, Integrative and Comparative Physiology - March 9, 2017 Category: Physiology Authors: McFarlane, S. V., Mathers, K. E., Staples, J. F. Tags: Research Article Source Type: research

Short-term intense exercise training reduces stress markers and alters the transcriptional response to exercise in skeletal muscle
The purpose of this investigation was to examine the influence of short-term intense endurance training on cycling performance, along with the acute and chronic signaling responses of skeletal muscle stress and stability markers. Ten recreationally active subjects (25 ± 2 yr, 79 ± 3 kg, 47 ± 2 ml·kg–1·min–1) were studied before and after a 12-day cycling protocol to examine the effects of short-term intense (70–100% Vo2max) exercise training on resting and exercise-induced regulation of molecular factors related to skeletal muscle cellular stress and protein stability. S...
Source: AJP: Regulatory, Integrative and Comparative Physiology - March 9, 2017 Category: Physiology Authors: Hinkley, J. M., Konopka, A. R., Suer, M. K., Harber, M. P. Tags: Research Article Source Type: research

Sequence and functional characterization of hypoxia-inducible factors, HIF1{alpha}, HIF2{alpha}a, and HIF3{alpha}, from the estuarine fish, Fundulus heteroclitus
The hypoxia-inducible factor (HIF) family of transcription factors plays central roles in the development, physiology, pathology, and environmental adaptation of animals. Because many aquatic habitats are characterized by episodes of low dissolved oxygen, fish represent ideal models to study the roles of HIF in the response to aquatic hypoxia. The estuarine fish Fundulus heteroclitus is found in habitats prone to hypoxia. It responds to low oxygen via behavioral, physiological, and molecular changes, and one member of the HIF family, HIF2α, has been previously described. Herein, cDNA sequencing, phylogenetic analyses...
Source: AJP: Regulatory, Integrative and Comparative Physiology - March 9, 2017 Category: Physiology Authors: Townley, I. K., Karchner, S. I., Skripnikova, E., Wiese, T. E., Hahn, M. E., Rees, B. B. Tags: Research Article Source Type: research

Acclimation to hypoxia increases carbohydrate use during exercise in high-altitude deer mice
The low O2 experienced at high altitude is a significant challenge to effective aerobic locomotion, as it requires sustained tissue O2 delivery in addition to the appropriate allocation of metabolic substrates. Here, we tested whether high- and low-altitude deer mice (Peromyscus maniculatus) have evolved different acclimation responses to hypoxia with respect to muscle metabolism and fuel use during submaximal exercise. Using F1 generation high- and low-altitude deer mice that were born and raised in common conditions, we assessed 1) fuel use during exercise, 2) metabolic enzyme activities, and 3) gene expression for key t...
Source: AJP: Regulatory, Integrative and Comparative Physiology - March 9, 2017 Category: Physiology Authors: Lau, D. S., Connaty, A. D., Mahalingam, S., Wall, N., Cheviron, Z. A., Storz, J. F., Scott, G. R., McClelland, G. B. Tags: Research Article Source Type: research

Inability to replete white adipose tissue during recovery phase of sepsis is associated with increased autophagy, apoptosis, and proteasome activity
Adipose tissue is an important energy depot and endocrine organ, and the degree of adiposity impacts the host response to infection. However, little is known regarding the mechanisms by which white adipose tissue (WAT) is lost acutely and then restored after the resolution of sepsis. Therefore, the signaling pathways governing protein synthesis, autophagy, apoptosis, and the ubiquitin-proteasome were investigated to identify potential mechanisms mediating the acute (24 h) loss of WAT after cecal ligation and puncture as well as the failure to replenish WAT during recovery (day 10). While whole body fat mass was decreased e...
Source: AJP: Regulatory, Integrative and Comparative Physiology - March 9, 2017 Category: Physiology Authors: Crowell, K. T., Soybel, D. I., Lang, C. H. Tags: Research Article Source Type: research

Seasonal expression of P450arom and estrogen receptors in scented glands of muskrats (Ondatra zibethicus)
In conclusion, the seasonal changes in the expression of P450arom and ERs may be involved in the regulation of scented gland functions. (Source: AJP: Regulatory, Integrative and Comparative Physiology)
Source: AJP: Regulatory, Integrative and Comparative Physiology - March 9, 2017 Category: Physiology Authors: Zhang, H., Lu, L., Zhu, M., Zhang, F., Sheng, X., Yuan, Z., Han, Y., Watanabe, G., Taya, K., Weng, Q. Tags: Research Article Source Type: research

Renal denervation in male rats with heart failure improves ventricular sympathetic nerve innervation and function
Heart failure is characterized by the loss of sympathetic innervation to the ventricles, contributing to impaired cardiac function and arrhythmogenesis. We hypothesized that renal denervation (RDx) would reverse this loss. Male Wistar rats underwent myocardial infarction (MI) or sham surgery and progressed into heart failure for 4 wk before receiving bilateral RDx or sham RDx. After additional 3 wk, left ventricular (LV) function was assessed, and ventricular sympathetic nerve fiber density was determined via histology. Post-MI heart failure rats displayed significant reductions in ventricular sympathetic innervation and t...
Source: AJP: Regulatory, Integrative and Comparative Physiology - March 9, 2017 Category: Physiology Authors: Pinkham, M. I., Loftus, M. T., Amirapu, S., Guild, S.-J., Quill, G., Woodward, W. R., Habecker, B. A., Barrett, C. J. Tags: Research Article Source Type: research

How consumer physical activity monitors could transform human physiology research
A sedentary lifestyle and lack of physical activity are well-established risk factors for chronic disease and adverse health outcomes. Thus, there is enormous interest in measuring physical activity in biomedical research. Many consumer physical activity monitors, including Basis Health Tracker, BodyMedia Fit, DirectLife, Fitbit Flex, Fitbit One, Fitbit Zip, Garmin Vivofit, Jawbone UP, MisFit Shine, Nike FuelBand, Polar Loop, Withings Pulse O2, and others have accuracies similar to that of research-grade physical activity monitors for measuring steps. This review focuses on the unprecedented opportunities that consumer phy...
Source: AJP: Regulatory, Integrative and Comparative Physiology - March 9, 2017 Category: Physiology Authors: Wright, S. P., Hall Brown, T. S., Collier, S. R., Sandberg, K. Tags: Review Source Type: research

Negative rebound in hippocampal neurogenesis following exercise cessation
This study examined the time-course profile of hippocampal neurogenesis following exercise cessation. Male C57BL/6 mice were randomly assigned to either a control (Con) or an exercise cessation (ExC) group. Mice in the ExC group were reared in a cage with a running wheel for 8 wk and subsequently placed in a standard cage to cease the exercise. Exercise resulted in a significant increase in the density of doublecortin (DCX)-positive immature neurons in the dentate gyrus (at week 0). Following exercise cessation, the density of DCX-positive neurons gradually decreased and was significantly lower than that in the Con group a...
Source: AJP: Regulatory, Integrative and Comparative Physiology - February 28, 2017 Category: Physiology Authors: Nishijima, T., Kamidozono, Y., Ishiizumi, A., Amemiya, S., Kita, I. Tags: Research Article Source Type: research

Orexin signaling in rostral lateral hypothalamus and nucleus accumbens shell in the control of spontaneous physical activity in high- and low-activity rats
Spontaneous physical activity (SPA) describes activity outside of formal exercise and shows large interindividual variability. The hypothalamic orexin/hypocretin peptides are key regulators of SPA. Orexins drive SPA within multiple brain sites, including rostral lateral hypothalamus (LH) and nucleus accumbens shell (NAcSh). Rats with high basal SPA (high activity, HA) show higher orexin mRNA expression and SPA after injection of orexin-A in rostral LH compared with low-activity (LA) rats. Here, we explored the contribution of orexin signaling in rostral LH and NAcSh to the HA/LA phenotype. We found that HA rats have higher...
Source: AJP: Regulatory, Integrative and Comparative Physiology - February 28, 2017 Category: Physiology Authors: Perez-Leighton, C., Little, M. R., Grace, M., Billington, C., Kotz, C. M. Tags: Research Article Source Type: research

Bidirectional crosstalk between the sensory and sympathetic motor systems innervating brown and white adipose tissue in male Siberian hamsters
The brain networks connected to the sympathetic motor and sensory innervations of brown (BAT) and white (WAT) adipose tissues were originally described using two transneuronally transported viruses: the retrogradely transported pseudorabies virus (PRV), and the anterogradely transported H129 strain of herpes simplex virus-1 (HSV-1 H129). Further complexity was added to this network organization when combined injections of PRV and HSV-1 H129 into either BAT or WAT of the same animal generated sets of coinfected neurons in the brain, spinal cord, and sympathetic and dorsal root ganglia. These neurons are well positioned to a...
Source: AJP: Regulatory, Integrative and Comparative Physiology - February 28, 2017 Category: Physiology Authors: Ryu, V., Watts, A. G., Xue, B., Bartness, T. J. Tags: Research Article Source Type: research