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.

Physiological and metabolic differences between visceral and subcutaneous adipose tissues in Nile tilapia (Oreochromis niloticus)
Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SCAT) have different structures and metabolic functions and play different roles in the regulation of the mammal endocrine system. However, little is known about morphology and physiological and metabolic functions between VAT and SCAT in fish. We compared the morphological, physiological, and biochemical characteristics of VAT and SCAT in Nile tilapia and measured their functions in energy intake flux, lipolytic ability, and gene expression patterns. SCAT contained more large adipocytes and nonadipocytes than VAT in Nile tilapia. VAT had higher lipid content a...
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 9, 2017 Category: Physiology Authors: Wang, Y.-W., Zhang, J.-L., Jiao, J.-G., Du, X.-X., Limbu, S. M., Qiao, F., Zhang, M.-L., Li, D.-L., Du, Z.-Y. Tags: Research Article Source Type: research

Diet-induced obesity accelerates blood lactate accumulation of rats in response to incremental exercise to maximum
This study examined whether blood lactate changes in response to incremental exercise is disrupted in obese animals. Muscular and hepatic proteins that are critical in lactate metabolism were also investigated. Rats were randomized to either standard chow (control) or high-fat diet (HFD) groups. All animals underwent an incremental treadmill test after 14 wk of diet intervention. Blood lactate levels were measured before and after the treadmill test. Activities of mitochondrial oxidative phosphorylation and glycolysis were examined in muscle tissues. Proteins in the liver and skeletal muscles that participate in the turnov...
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 9, 2017 Category: Physiology Authors: Chen, C.-N., Liao, Y.-H., Lin, S.-Y., Yu, J.-X., Li, Z.-J., Lin, Y.-C., Chang, G.-J., Lin, C.-H., Wong, A. M.-K. Tags: Research Article Source Type: research

Face cooling increases blood pressure during central hypovolemia
A reduction in central blood volume can lead to cardiovascular decompensation (i.e., failure to maintain blood pressure). Cooling the forehead and cheeks using ice water raises blood pressure. Therefore, face cooling (FC) could be used to mitigate decreases in blood pressure during central hypovolemia. We tested the hypothesis that FC during central hypovolemia induced by lower-body negative pressure (LBNP) would increase blood pressure. Ten healthy participants (22 ± 2 yr, three women, seven men) completed two randomized LBNP trials on separate days. Trials began with 30 mmHg of LBNP for 6 min. Then, a 2.5-liter pl...
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 9, 2017 Category: Physiology Authors: Johnson, B. D., Sackett, J. R., Sarker, S., Schlader, Z. J. Tags: Research Article Source Type: research

Filling the void: a role for exercise-induced BDNF and brain amyloid precursor protein processing
Inactivity, obesity, and insulin resistance are significant risk factors for the development of Alzheimer’s disease (AD). Several studies have demonstrated that diet-induced obesity, inactivity, and insulin resistance exacerbate the neuropathological hallmarks of AD. The aggregation of β-amyloid peptides is one of these hallmarks. β-Site amyloid precursor protein-cleaving enzyme 1 (BACE1) is the rate-limiting enzyme in amyloid precursor protein (APP) processing, leading to β-amyloid peptide formation. Understanding how BACE1 content and activity are regulated is essential for establishing therapies aim...
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 9, 2017 Category: Physiology Authors: MacPherson, R. E. K. Tags: Review Source Type: research

The 2017 New Investigator Review Awards
(Source: AJP: Regulatory, Integrative and Comparative Physiology)
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 9, 2017 Category: Physiology Authors: Samson, W. K. Tags: Editorial Source Type: research

Elucidating the role of leptin in systemic inflammation: a study targeting physiological leptin levels in rats and their macrophages
To elucidate the role of leptin in acute systemic inflammation, we investigated how its infusion at low, physiologically relevant doses affects the responses to bacterial lipopolysaccharide (LPS) in rats subjected to 24 h of food deprivation. Leptin was infused subcutaneously (0–20 μg·kg–1·h–1) or intracerebroventricularly (0–1 μg·kg–1·h–1). Using hypothermia and hypotension as biomarkers of systemic inflammation, we identified the phase extending from 90 to 240 min post-LPS as the most susceptible to modulation by leptin. In this phase, leptin suppresse...
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 1, 2017 Category: Physiology Authors: Flatow, E. A., Komegae, E. N., Fonseca, M. T., Brito, C. F., Musteata, F. M., Antunes-Rodrigues, J., Steiner, A. A. Tags: Research Article Source Type: research

Obesity-induced vascular inflammation involves elevated arginase activity
Obesity-induced vascular dysfunction involves pathological remodeling of the visceral adipose tissue (VAT) and increased inflammation. Our previous studies showed that arginase 1 (A1) in endothelial cells (ECs) is critically involved in obesity-induced vascular dysfunction. We tested the hypothesis that EC-A1 activity also drives obesity-related VAT remodeling and inflammation. Our studies utilized wild-type and EC-A1 knockout (KO) mice made obese by high-fat/high-sucrose (HFHS) diet. HFHS diet induced increases in body weight, fasting blood glucose, and VAT expansion. This was accompanied by increased arginase activity an...
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 1, 2017 Category: Physiology Authors: Yao, L., Bhatta, A., Xu, Z., Chen, J., Toque, H. A., Chen, Y., Xu, Y., Bagi, Z., Lucas, R., Huo, Y., Caldwell, R. B., Caldwell, R. W. Tags: Research Article Source Type: research

Regulation of energy metabolism during social interactions in rainbow trout: a role for AMP-activated protein kinase
Rainbow trout (Oncorhynchus mykiss) confined in pairs form social hierarchies in which subordinate fish typically experience fasting and high circulating cortisol levels, resulting in low growth rates. The present study investigated the role of AMP-activated protein kinase (AMPK) in mediating metabolic adjustments associated with social status in rainbow trout. After 3 days of social interaction, liver AMPK activity was significantly higher in subordinate than dominant or sham (fish handled in the same fashion as paired fish but held individually) trout. Elevated liver AMPK activity in subordinate fish likely reflected a s...
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 1, 2017 Category: Physiology Authors: Gilmour, K. M., Craig, P. M., Dhillon, R. S., Lau, G. Y., Richards, J. G. Tags: Research Article Source Type: research

Energy homeostasis in apolipoprotein AIV and cholecystokinin-deficient mice
Apolipoprotein AIV (ApoAIV) and cholecystokinin (CCK) are well-known satiating signals that are stimulated by fat consumption. Peripheral ApoAIV and CCK interact to prolong satiating signals. In the present study, we hypothesized that ApoAIV and CCK control energy homeostasis in response to high-fat diet feeding. To test this hypothesis, energy homeostasis in ApoAIV and CCK double knockout (ApoAIV/CCK-KO), ApoAIV knockout (ApoAIV-KO), and CCK knockout (CCK-KO) mice were monitored. When animals were maintained on a low-fat diet, ApoAIV/CCK-KO, ApoAIV-KO, and CCK-KO mice had comparable energy intake and expenditure, body wei...
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 1, 2017 Category: Physiology Authors: Weng, J., Lou, D., Benoit, S. C., Coschigano, N., Woods, S. C., Tso, P., Lo, C. C. Tags: Research Article Source Type: research

Effect of circulating glucagon and free fatty acids on hepatic FGF21 production in dairy cows
Modern dairy cows meet the energy demand of early lactation by calling on hormonally driven mechanisms to increase the use of lipid reserves. In this context, we recently reported that fibroblast growth factor-21 (FGF21), a hormone required for efficient use of lipid reserves in rodents, is upregulated in periparturient dairy cows. Increased plasma FGF21 in early lactation coincides with elevated circulating concentrations of glucagon (GCG) and nonesterified fatty acids (NEFA). To assess the relative contribution of these factors in regulating FGF21, two experiments were performed in energy-sufficient, nonpregnant, nonlact...
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 1, 2017 Category: Physiology Authors: Caixeta, L. S., Giesy, S. L., Krumm, C. S., Perfield, J. W., Butterfield, A., Schoenberg, K. M., Beitz, D. C., Boisclair, Y. R. Tags: Research Article Source Type: research

Flow-mediated dilation and peripheral arterial tonometry are disturbed in preeclampsia and reflect different aspects of endothelial function
In this study, we made a comprehensive evaluation of in vivo vascular function [including flow-mediated dilatation (FMD), peripheral arterial tonometry (PAT), and arterial stiffness] in preeclamptic patients and compared them with normal pregnancies. In addition, we assessed the relation between vascular function and systemic inflammation. Fourteen patients with preeclampsia (PE) and 14 healthy pregnant controls were included. Endothelial function was determined by FMD and PAT and arterial stiffness by carotid-femoral pulse-wave velocity and augmentation index. Systemic inflammation was assessed using mean platelet volume ...
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 1, 2017 Category: Physiology Authors: Mannaerts, D., Faes, E., Goovaerts, I., Stoop, T., Cornette, J., Gyselaers, W., Spaanderman, M., Van Craenenbroeck, E. M., Jacquemyn, Y. Tags: Research Article Source Type: research

Cyclical blood flow restriction resistance exercise: a potential parallel to remote ischemic preconditioning?
Remote ischemic preconditioning (RIPC) is characterized by the cyclical application of limb blood flow restriction and reperfusion and has been shown to protect vital organs during a subsequent ischemic insult. Blood flow restriction exercise (BFRE) similarly combines bouts of blood flow restriction with low-intensity exercise and thus could potentially emulate the protection demonstrated by RIPC. One concern with BFRE, however, is the potential for an augmented rise in sympathetic outflow due to greater activation of the exercise pressor reflex. Because of the use of lower workloads, however, we hypothesized that BFRE wou...
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 1, 2017 Category: Physiology Authors: Sprick, J. D., Rickards, C. A. Tags: Research Article Source Type: research

Combining remote ischemic preconditioning and aerobic exercise: a novel adaptation of blood flow restriction exercise
Remote ischemic preconditioning (RIPC) can attenuate tissue damage sustained by ischemia-reperfusion injury. Blood flow restriction exercise (BFRE) restricts blood flow to exercising muscles. We implemented a novel approach to BFRE with cyclical bouts of blood flow restriction-reperfusion, reflecting the RIPC model. A concern about BFRE, however, is potential amplification of the exercise pressor reflex, which could be unsafe in at-risk populations. We hypothesized that cyclical BFRE would elicit greater increases in sympathetic outflow and arterial pressure than conventional exercise (CE) when performed at the same relati...
Source: AJP: Regulatory, Integrative and Comparative Physiology - November 1, 2017 Category: Physiology Authors: Sprick, J. D., Rickards, C. A. Tags: Research Article Source Type: research

Respiratory muscle endurance training reduces the O2 cost of cycling and perceived exertion in obese adolescents
In obesity, the increased O2 cost of breathing negatively affects the O2 cost of exercise and exercise tolerance. The purpose of the study was to determine whether, in obese adolescents, the addition of respiratory muscle endurance training (RMET) (isocapnic hyperpnea) to a standard body mass reduction program decreases the O2 cost of exercise and perceived exertion. Nine male obese adolescents [16.0 ± 1.4 yr (x ± SD), body mass 114.4 ± 22.3 kg] underwent 3 wk of RMET (5 days/week) in addition to a standard body mass reduction program. Eight age- and sex-matched obese adolescents underwent only the sta...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 9, 2017 Category: Physiology Authors: Salvadego, D., Sartorio, A., Agosti, F., Tringali, G., Patrizi, A., Isola, M., LoMauro, A., Aliverti, A., Grassi, B. Tags: Research Article Source Type: research

High-protein diet improves sensitivity to cholecystokinin and shifts the cecal microbiome without altering brain inflammation in diet-induced obesity in rats
High-protein diet (HPD) curtails obesity and/or fat mass, but it is unknown whether it reverses neuroinflammation or alters glucose levels, CCK sensitivity, and gut microbiome in rats fed a Western diet (WD)-induced obesity (DIO). Male rats fed a WD (high fat and sugar) for 12 wk were switched to a HPD for 6 wk. Body composition, food intake, meal pattern, sensitivity to intraperitoneal CCK-8S, blood glucose, brain signaling, and cecal microbiota were assessed. When compared with a normal diet, WD increased body weight (9.3%) and fat mass (73.4%). CCK-8S (1.8 or 5.2 nmol/kg) did not alter food intake and meal pattern in DI...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 9, 2017 Category: Physiology Authors: Wang, L., Jacobs, J. P., Lagishetty, V., Yuan, P.-Q., Wu, S. V., Million, M., Reeve, J. R., Pisegna, J. R., Tache, Y. Tags: Research Article Source Type: research