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.

Development of an animal-borne blood sample collection device and its deployment for the determination of cardiovascular and stress hormones in phocid seals
An animal-borne blood sampler with data-logging functions was developed for phocid seals, which collected two blood samples for the comparison of endocrinological/biochemical parameters under two different conditions. The sampler can be triggered by preset hydrostatic pressure, acceleration (descending or ascending), temperature, and time, and also manually by light. The sampling was reliable with 39/50 (78%) successful attempts to collect blood samples. Contamination of fluids in the tubing to the next blood sample was <1%, following the prior clearance of the tubing to a waste syringe. In captive harbor seals (Phoca v...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 5, 2016 Category: Physiology Authors: Takei, Y., Suzuki, I., Wong, M. K. S., Milne, R., Moss, S., Sato, K., Hall, A. Tags: Cardiovascular and Renal Integration Source Type: research

Antilipolytic and antilipogenic effects of the CPT-1b inhibitor oxfenicine in the white adipose tissue of rats
Oxfenicine is a carnitine-palmitoyl transferase 1b (CPT-1b)-specific inhibitor that has been shown to improve whole body insulin sensitivity while suppressing fatty acid (FA) oxidation and increasing circulating FA. Because the white adipose tissue (WAT) is an organ that stores and releases FAs, this study investigated whether oxfenicine-induced inhibition of FA oxidation affected adiposity and WAT metabolism in rats fed either low (LF) or high-fat (HF) diets. Following 8 wk of dietary intervention, male Sprague-Dawley rats were given a daily intraperitoneal injection of oxfenicine (150 mg/kg body wt) or vehicle (PBS) for ...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 5, 2016 Category: Physiology Authors: Sepa-Kishi, D. M., Wu, M. V., Uthayakumar, A., Mohasses, A., Ceddia, R. B. Tags: Obesity, Diabetes and Energy Homeostasis Source Type: research

Adaptation to a high-protein diet progressively increases the postprandial accumulation of carbon skeletons from dietary amino acids in rats
We aimed to determine whether oxidative pathways adapt to the overproduction of carbon skeletons resulting from the progressive activation of amino acid (AA) deamination and ureagenesis under a high-protein (HP) diet. Ninety-four male Wistar rats, of which 54 were implanted with a permanent jugular catheter, were fed a normal protein diet for 1 wk and were then switched to an HP diet for 1, 3, 6, or 14 days. On the experimental day, they were given their meal containing a mixture of 20 U-[15N]-[13C] AA, whose metabolic fate was followed for 4 h. Gastric emptying tended to be slower during the first 3 days of adaptation. 15...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 5, 2016 Category: Physiology Authors: Stepien, M., Azzout-Marniche, D., Even, P. C., Khodorova, N., Fromentin, G., Tome, D., Gaudichon, C. Tags: Obesity, Diabetes and Energy Homeostasis Source Type: research

IL-6 ameliorates defective leptin sensitivity in DIO ventromedial hypothalamic nucleus neurons
Rats selectively bred to develop diet-induced obesity (DIO) have an early onset reduction in the sensitivity of their ventromedial hypothalamic nucleus (VMN) neurons to leptin compared with diet-resistant (DR) rats. This reduced sensitivity includes decreased leptin receptor (Lepr-b) mRNA expression, leptin receptor binding, leptin-induced phosphorylation of STAT3 (pSTAT3), and impaired leptin excitation (LepE) of VMN neurons. When administered exogenously, the pancreatic peptide, amylin, acts synergistically to reduce food intake and body weight in obese, leptin-resistant DIO rats by increasing VMN leptin signaling, likel...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 5, 2016 Category: Physiology Authors: Larsen, L., Le Foll, C., Dunn-Meynell, A. A., Levin, B. E. Tags: Neural Control Source Type: research

Impaired utilization of membrane potential by complex II-energized mitochondria of obese, diabetic mice assessed using ADP recycling methodology
Recently, we used an ADP recycling approach to examine mouse skeletal muscle (SkM) mitochondrial function over respiratory states intermittent between state 3 and 4. We showed that respiration energized at complex II by succinate, in the presence of rotenone to block complex I, progressively increased with incremental additions of ADP. However, in the absence of rotenone, respiration peaked at low [ADP] but then dropped markedly as [ADP] was further increased. Here, we tested the hypothesis that these respiratory dynamics would differ between mitochondria of mice fed high fat (HF) and treated with a low dose of streptozoto...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 5, 2016 Category: Physiology Authors: Fink, B. D., Bai, F., Yu, L., Sivitz, W. I. Tags: Obesity, Diabetes and Energy Homeostasis Source Type: research

Post-oral sugar detection rapidly and chemospecifically modulates taste-guided behavior
Several recent studies have shown that post-oral sugar sensing rapidly stimulates ingestion. Here, we explored the specificity with which early-phase post-oral sugar sensing influenced ingestive motivation. In experiment 1, rats were trained to associate the consumption of 0.3 M sucrose with injections of LiCl (3.0 meq/kg ip, conditioned taste aversion) or given equivalent exposures to the stimuli, but in an unpaired fashion. Then, all rats were subjected to two brief-access tests to assess appetitive and consummatory responses to the taste properties of sucrose (0.01–1.0 M), 0.12 M NaCl, and dH2O (in 10-s trials in ...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 5, 2016 Category: Physiology Authors: Schier, L. A., Spector, A. C. Tags: Obesity, Diabetes and Energy Homeostasis Source Type: research

Carotid baroreflex control of heart rate is enhanced, while control of mean arterial pressure is preserved during whole body heat stress in young healthy men
Whole body heat stress (WBH) results in numerous cardiovascular alterations that ultimately reduce orthostatic tolerance. While impaired carotid baroreflex (CBR) function during WBH has been reported as a potential reason for this decrement, study design considerations may limit interpretation of previous findings. We sought to test the hypothesis that CBR function is unaltered during WBH. CBR function was assessed in 10 healthy male subjects (age: 26 ± 3; height: 185 ± 7 cm; weight: 82 ± 10 kg; BMI: 24 ± 3 kg/m2; means ± SD) using 5-s trials of neck pressure (+45, +30, and +15 Torr) and ...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 5, 2016 Category: Physiology Authors: Krnjajic, D., Allen, D. R., Butts, C. L., Keller, D. M. Tags: Neural Control Source Type: research

{alpha}4-Containing nicotinic receptors contribute to the effects of perinatal nicotine on ventilatory and metabolic responses of neonatal mice to ambient cooling
Among numerous studies, perinatal nicotine exposure (PN) has had variable effects on respiratory control in the neonatal period. The effects of acute nicotine exposure on breathing are largely mediated by α4-containing nicotine acetylcholine receptors (nAChRs). These receptors are also involved in thermoregulatory responses induced by both acetylcholine and nicotine. We therefore hypothesized that α4-containing nAChRs would mediate the effects of PN on the metabolic and ventilatory responses of neonates to modest cold exposure. Wild-type (WT) and α4 knockout (KO) mice were exposed to 6 mg·kg–...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 5, 2016 Category: Physiology Authors: Avraam, J., Cummings, K. J., Frappell, P. B. Tags: Rapid Report Source Type: research

Endothelin research and the discovery of macitentan for the treatment of pulmonary arterial hypertension
Endothelin receptor antagonists (ERAs) are used for the treatment of pulmonary arterial hypertension (PAH). Macitentan, a dual (ETA+ETB) ERA approved for the long-term treatment of PAH, was discovered through a tailored research program aimed at improving efficacy and safety over the existing ERAs. The goal of improved efficacy was based on the understanding that not only the ETA receptor but also the ETB receptor contributed to the hemodynamic and structural changes induced by endothelin-1 (ET-1) in pathological conditions and on the predefined requirements for optimal tissue penetration and binding kinetics of the antago...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 5, 2016 Category: Physiology Authors: Clozel, M. Tags: Review Source Type: research

Sex differences in obesity-induced hypertension and vascular dysfunction: a protective role for estrogen in adipose tissue inflammation?
Obesity is a potent predictor of cardiovascular disease and associated risk factors, including hypertension. Systemic inflammation has been suggested by a number of studies to be an important link between excess adiposity and hypertension, yet the majority of the studies have been conducted exclusively in males. This is problematic since women represent ~53% of hypertensive cases and are more likely than men to be obese. There is a growing body of literature supporting a central role for immune cell activation in numerous experimental models of hypertension, and both the sex of the subject and the sex of the T cell have be...
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 5, 2016 Category: Physiology Authors: Taylor, L. E., Sullivan, J. C. Tags: Call for Papers Source Type: research

Oxytocin redux
(Source: AJP: Regulatory, Integrative and Comparative Physiology)
Source: AJP: Regulatory, Integrative and Comparative Physiology - October 5, 2016 Category: Physiology Authors: Samson, W. K. Tags: Editorial Source Type: research

Major contribution of central pulmonary reservoir discharge to increased pulmonary arterial diastolic blood flow after birth in near-term lambs
Recent fetal lamb data have suggested that the pulmonary trunk (PT) region displays a reservoir function and that a pharmacologically induced fall in pulmonary vascular resistance (PVR) increases and redistributes diastolic discharge from this central pulmonary reservoir toward the lungs, thereby producing a positive diastolic offset in the pulmonary arterial (PA) blood flow profile. As a similar offset in PA flow characteristically occurs after birth, this study tested the hypotheses that 1) central pulmonary reservoir discharge is both redistributed toward the lungs and increased in magnitude during the birth transition ...
Source: AJP: Regulatory, Integrative and Comparative Physiology - September 30, 2016 Category: Physiology Authors: Smolich, J. J., Mynard, J. P. Tags: Hormones, Reproduction and Development Source Type: research

Developmental cardiorespiratory physiology of the air-breathing tropical gar, Atractosteus tropicus
The physiological transition to aerial breathing in larval air-breathing fishes is poorly understood. We investigated gill ventilation frequency (fG), heart rate (fH), and air breathing frequency (fAB) as a function of development, activity, hypoxia, and temperature in embryos/larvae from day (D) 2.5 to D30 posthatch of the tropical gar, Atractosteus tropicus, an obligate air breather. Gill ventilation at 28°C began at approximately D2, peaking at ~75 beats/min on D5, before declining to ~55 beats/min at D30. Heart beat began ~36–48 h postfertilization and ~1 day before hatching. fH peaked between D3 and D10 at ~...
Source: AJP: Regulatory, Integrative and Comparative Physiology - September 30, 2016 Category: Physiology Authors: Burggren, W. W., Bautista, G. M., Coop, S. C., Couturier, G. M., Delgadillo, S. P., Garcia, R. M., Gonzalez, C. A. A. Tags: Cardiovascular and Renal Integration Source Type: research

Deletion of soluble epoxide hydrolase enhances coronary reactive hyperemia in isolated mouse heart: role of oxylipins and PPAR{gamma}
The relationship between soluble epoxide hydrolase (sEH) and coronary reactive hyperemia (CRH) response to a brief ischemic insult is not known. Epoxyeicosatrienoic acids (EETs) exert cardioprotective effects in ischemia/reperfusion injury. sEH converts EETs into dihydroxyeicosatrienoic-acids (DHETs). Therefore, we hypothesized that knocking out sEH enhances CRH through modulation of oxylipin profiles, including an increase in EET/DHET ratio. Compared with sEH+/+, sEH–/– mice showed enhanced CRH, including greater repayment volume (RV; 28% higher, P < 0.001) and repayment/debt ratio (32% higher, P < 0.001...
Source: AJP: Regulatory, Integrative and Comparative Physiology - September 30, 2016 Category: Physiology Authors: Hanif, A., Edin, M. L., Zeldin, D. C., Morisseau, C., Nayeem, M. A. Tags: Cardiovascular and Renal Integration Source Type: research

Heart rate variability during high heat stress: a comparison between young and older adults with and without Type 2 diabetes
In conclusion, when compared with young, older individuals with and without T2D demonstrate low HRV at baseline and less change in HRV (including an attenuated sympathetic response) during 3 h high heat stress, potentially contributing to impaired thermoregulatory function. (Source: AJP: Regulatory, Integrative and Comparative Physiology)
Source: AJP: Regulatory, Integrative and Comparative Physiology - September 30, 2016 Category: Physiology Authors: Carrillo, A. E., Flouris, A. D., Herry, C. L., Poirier, M. P., Boulay, P., Dervis, S., Friesen, B. J., Malcolm, J., Sigal, R. J., Seely, A. J. E., Kenny, G. P. Tags: Obesity, Diabetes and Energy Homeostasis Source Type: research