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.

Oxygen signaling: Call for papers
(Source: AJP: Regulatory, Integrative and Comparative Physiology)
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 9, 2016 Category: Physiology Authors: Evans, R. G. Tags: Editorial Source Type: research

Hypercapnic ventilatory response is decreased in a mouse model of excessive erythrocytosis
The impact of cerebral erythropoietin (Epo) in the regulation of the hypercapnic ventilatory response (HcVR) is controversial. While we reported that cerebral Epo does not affect the central chemosensitivity in C57Bl6 mice receiving an intracisternal injection of sEpoR (the endogenous antagonist of Epo), a recent study in transgenic mice with constitutive high levels of human Epo in brain and circulation (Tg6) and in brain only (Tg21), showed that Epo blunts the HcVR, maybe by interacting with central and peripheral chemoreceptors. High Epo serum levels in Tg6 mice lead to excessive erythrocytosis (hematocrit ~80–90%...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: Laouafa, S., Elliot-Portal, E., Revollo, S., Schneider Gasser, E. M., Joseph, V., Voituron, N., Gassmann, M., Soliz, J. Tags: Neural control Source Type: research

Dorsomedial hypothalamic NPY affects cholecystokinin-induced satiety via modulation of brain stem catecholamine neuronal signaling
Increased neuropeptide Y (NPY) gene expression in the dorsomedial hypothalamus (DMH) has been shown to cause hyperphagia, but the pathway underlying this effect remains less clear. Hypothalamic neural systems play a key role in the control of food intake, in part, by modulating the effects of meal-related signals, such as cholecystokinin (CCK). An increase in DMH NPY gene expression decreases CCK-induced satiety. Since activation of catecholaminergic neurons within the nucleus of solitary tract (NTS) contributes to the feeding effects of CCK, we hypothesized that DMH NPY modulates NTS neural catecholaminergic signaling to ...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: de La Serre, C. B., Kim, Y. J., Moran, T. H., Bi, S. Tags: Neural control Source Type: research

Predominant cause of prolonged low-frequency force depression changes during recovery after in situ fatiguing stimulation of rat fast-twitch muscle
To investigate time-dependent changes in sarcoplasmic reticulum (SR) Ca2+ release and myofibrillar (my-) Ca2+ sensitivity during recovery from prolonged low-frequency force depression (PLFFD), rat gastrocnemius muscles were electrically stimulated in situ. After 0 h (R0), 0.5 h (R0.5), 2 h (R2), 6 h (R6), or 12 h of recovery, the superficial gastrocnemius muscles were excised and used for biochemical and skinned fiber analyses. At R0, R0.5, R2, and R6, the ratio of force at 1 Hz to that at 50 Hz was decreased in the skinned fibers. The ratio of depolarization-induced force to the maximum Ca2+-activated force (depol/Ca2+ fo...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: Watanabe, D., Wada, M. Tags: Physical activity and inactivity Source Type: research

Advances in Technology: Blood-sampling at depth. Focus on "Development of an animal-borne blood sample collection device and its deployment for the determination of cardiovascular and stress hormones in submerged phocid seals"
(Source: AJP: Regulatory, Integrative and Comparative Physiology)
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: Ponganis, P. J. Tags: Editorial Focus Source Type: research

Metabolic pathways of lung inflammation revealed by high-resolution metabolomics (HRM) of H1N1 influenza virus infection in mice
Influenza is a significant health concern worldwide. Viral infection induces local and systemic activation of the immune system causing attendant changes in metabolism. High-resolution metabolomics (HRM) uses advanced mass spectrometry and computational methods to measure thousands of metabolites inclusive of most metabolic pathways. We used HRM to identify metabolic pathways and clusters of association related to inflammatory cytokines in lungs of mice with H1N1 influenza virus infection. Infected mice showed progressive weight loss, decreased lung function, and severe lung inflammation with elevated cytokines [interleuki...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: Chandler, J. D., Hu, X., Ko, E.-J., Park, S., Lee, Y.-T., Orr, M., Fernandes, J., Uppal, K., Kang, S.-M., Jones, D. P., Go, Y.-M. Tags: Respiration Source Type: research

Effects of estrogen replacement on stress-induced cardiovascular responses via renin-angiotensin system in ovariectomized rats
The purpose of this study was to determine whether chronic estrogen replacement in ovariectomized rats inhibits the pressor response to psychological stress by attenuating the activation of the renin-angiotensin system. Female Wistar rats aged 9 wk were ovariectomized. After 4 wk, the rats were randomly assigned to be implanted subcutaneously with pellets containing either 17β-estradiol (E2) or placebo (Pla). After 4 wk of treatment, the rats underwent cage-switch stress and, in a separate experiment, a subset received an infusion of angiotensin II. The cage-switch stress rapidly elevated blood pressure (BP) and heart...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: Tazumi, S., Yokota, N., Kawakami, M., Omoto, S., Takamata, A., Morimoto, K. Tags: Hormones, reproduction and development Source Type: research

Chronic binge alcohol administration impairs glucose-insulin dynamics and decreases adiponectin in asymptomatic simian immunodeficiency virus-infected macaques
Alcohol use disorders (AUDs) frequently exist among persons living with HIV/AIDS. Chronic alcohol consumption, HIV infection, and antiretroviral therapy (ART) are independently associated with impairments in glucose-insulin dynamics. Previous studies from our laboratory have shown that chronic binge alcohol (CBA) administration decreases body mass index, attenuates weight gain, and accentuates skeletal muscle wasting at end-stage disease in non-ART-treated simian immunodeficiency virus (SIV)-infected male rhesus macaques. The aim of this study was to investigate whether CBA and ART alone or in combination alter body compos...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: Ford, S. M., Simon, L., Vande Stouwe, C., Allerton, T., Mercante, D. E., Byerley, L. O., Dufour, J. P., Bagby, G. J., Nelson, S., Molina, P. E. Tags: Obesity, diabetes and energy homeostasis Source Type: research

Intramyocellular ceramides and skeletal muscle mitochondrial respiration are partially regulated by Toll-like receptor 4 during hindlimb unloading
Physical inactivity and disuse result in skeletal muscle metabolic disruption, including insulin resistance and mitochondrial dysfunction. The role of the Toll-like receptor 4 (TLR4) signaling pathway in contributing to metabolic decline with muscle disuse is unknown. Therefore, our goal was to determine whether TLR4 is an underlying mechanism of insulin resistance, mitochondrial dysfunction, and skeletal muscle ceramide accumulation following muscle disuse in mice. To address this hypothesis, we subjected (n = 6–8/group) male WT and TLR4–/– mice to 2 wk of hindlimb unloading (HU), while a second group of...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: Kwon, O. S., Nelson, D. S., Barrows, K. M., O'Connell, R. M., Drummond, M. J. Tags: Obesity, diabetes and energy homeostasis Source Type: research

Carotid baroreflex function at the onset of cycling in men
Arterial baroreflex function is important for blood pressure control during exercise, but its contribution to cardiovascular adjustments at the onset of cycling exercise remains unclear. Fifteen healthy male subjects (24 ± 1 yr) performed 45-s trials of low- and moderate-intensity cycling, with carotid baroreceptor stimulation by neck suction at –60 Torr applied 0–5, 10–15, and 30–35 s after the onset of exercise. Cardiovascular responses to neck suction during cycling were compared with those obtained at rest. An attenuated reflex decrease in heart rate following neck suction was detected du...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: Barbosa, T. C., Vianna, L. C., Hashimoto, T., Petersen, L. G., Olesen, N. D., Tsukamoto, H., Sorensen, H., Ogoh, S., Nobrega, A. C. L., Secher, N. H. Tags: Neural control Source Type: research

Hypoxia-induced contraction of chicken embryo mesenteric arteries: mechanisms and developmental changes
In conclusion, the results of the present study demonstrate that hypoxic vasoconstriction is an intrinsic feature of chicken MA vascular smooth muscle cells during late embryogenesis and the perinatal period. (Source: AJP: Regulatory, Integrative and Comparative Physiology)
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: Brinks, L., Moonen, R. M. J., Moral-Sanz, J., Barreira, B., Kessels, L., Perez-Vizcaino, F., Cogolludo, A., Villamor, E. Tags: Call for Papers Source Type: research

Nitric oxide synthase-mediated blood pressure regulation in obese melanocortin-4 receptor-deficient pregnant rats
We examined the impact of obesity on NO synthase (NOS)-mediated regulation of blood pressure during pregnancy by testing the hypothesis that NOS activity, expression, and regulation of vascular tone and blood pressure are reduced in obese pregnant rats. At gestational day 19, melanocortin-4 receptor (MC4R)-deficient obese rats (MC4R) had greater body weight and fat mass with elevated blood pressure and circulating sFlt-1 levels compared with MC4R pregnant rats. MC4R pregnant rats also had less circulating cGMP levels and reduced total NOS enzymatic activity and expression in mesenteric arteries. Despite decreased biochemic...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: Spradley, F. T., Sasser, J. M., Musall, J. B., Sullivan, J. C., Granger, J. P. Tags: Call for Papers Source Type: research

Endothelial and inflammatory responses to acute exercise in perimenopausal and late postmenopausal women
Endothelial dysfunction and inflammation are characteristics of subclinical atherosclerosis and may increase through progressive menopausal stages. Evaluating endothelial responses to acute exercise can reveal underlying dysfunction not apparent in resting conditions. The purpose of this study was to investigate markers of endothelial function and inflammation before and after acute exercise in healthy low-active perimenopausal (PERI) and late postmenopausal (POST) women. Flow-mediated dilation (FMD), CD31+/CD42b– and CD62E+ endothelial microparticles (EMPs), and the circulating inflammatory factors monocyte chemoatt...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: Serviente, C., Troy, L. M., de Jonge, M., Shill, D. D., Jenkins, N. T., Witkowski, S. Tags: Call for Papers Source Type: research

Reassessing wanting and liking in the study of mesolimbic influence on food intake
Humans and animals such as rats and mice tend to overconsume calorie-dense foods, a phenomenon that likely contributes to obesity. One often-advanced explanation for why we preferentially consume sweet and fatty foods is that they are more "rewarding" than low-calorie foods. "Reward" has been subdivided into three interdependent psychological processes: hedonia (liking a food), reinforcement (formation of associations among stimuli, actions, and/or the food), and motivation (wanting the food). Research into these processes has focused on the mesolimbic system, which comprises both dopamine neurons in the ventral tegmental ...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: Nicola, S. M. Tags: Review Source Type: research

Diffusive shunting of gases and other molecules in the renal vasculature: physiological and evolutionary significance
Countercurrent systems have evolved in a variety of biological systems that allow transfer of heat, gases, and solutes. For example, in the renal medulla, the countercurrent arrangement of vascular and tubular elements facilitates the trapping of urea and other solutes in the inner medulla, which in turn enables the formation of concentrated urine. Arteries and veins in the cortex are also arranged in a countercurrent fashion, as are descending and ascending vasa recta in the medulla. For countercurrent diffusion to occur, barriers to diffusion must be small. This appears to be characteristic of larger vessels in the renal...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 31, 2016 Category: Physiology Authors: Ngo, J. P., Ow, C. P. C., Gardiner, B. S., Kar, S., Pearson, J. T., Smith, D. W., Evans, R. G. Tags: Review Source Type: research