AJP: Regulatory, Integrative and Comparative Physiology AJP: Regulatory, Integrative and Comparative Physiology RSS feedThis 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.

Thermoregulatory inversion: a novel thermoregulatory paradigm
To maintain core body temperature in mammals, the normal central nervous system (CNS) thermoregulatory reflex networks produce an increase in brown adipose tissue (BAT) thermogenesis in response to skin cooling and an inhibition of the sympathetic outflow to BAT during skin rewarming. In contrast, these normal thermoregulatory reflexes appear to be inverted in hibernation/torpor; thermogenesis is inhibited during exposure to a cold environment, allowing dramatic reductions in core temperature and metabolism, and thermogenesis is activated during skin rewarming, contributing to a return of normal body temperature. Here, we ...
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 30, 2017 Category: Physiology Authors: Tupone, D., Cano, G., Morrison, S. F. Tags: Research Article Source Type: research

Longitudinal characterization of renal proximal tubular markers in normotensive and preeclamptic pregnancies
In conclusion, proximal tubular dysfunction, as assessed by A1M and C5b-9, developed during the interval between the end of the second trimester and delivery in patients with PE. However, this was not matched by abnormalities in markers previously associated with tubular cell injury (KIM-1, IGFBP-7, and TIMP-2). (Source: AJP: Regulatory, Integrative and Comparative Physiology)
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 30, 2017 Category: Physiology Authors: Codsi, E., Garovic, V. D., Gonzalez-Suarez, M. L., Milic, N., Borowski, K. S., Rose, C. H., Davies, N. P., Kashani, K. B., Lieske, J. C., White, W. M. Tags: Research Article Source Type: research

Expression and localization of pannexin-1 and CALHM1 in porcine bladder and their involvement in modulating ATP release
ATP release from urinary bladder is vital for afferent signaling. The aims of this study were to localize calcium homeostasis modulator 1 (CALHM1) and pannexin-1 expression and to determine their involvement in mediating ATP release in the bladder. To determine gene expression and cellular distribution, PCR and immunohistochemistry were performed, respectively, in the porcine bladder. CALHM1 and pannexin-1-mediated ATP release in response to hypotonic solution (0.45% NaCl)-induced stretch, and extracellular Ca2+ depletion ([Ca2+]0) was measured in isolated urothelial, suburothelial, and detrusor muscle cells. CALHM1 and pa...
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 30, 2017 Category: Physiology Authors: Sana-Ur-Rehman, H., Markus, I., Moore, K. H., Mansfield, K. J., Liu, L. Tags: Research Article Source Type: research

Long-term HIF-1{alpha} transcriptional activation is essential for heat-acclimation-mediated cross tolerance: mitochondrial target genes
An important adaptive feature of heat acclimation (HA) is the induction of cross tolerance against novel stressors (HACT) Reprogramming of gene expression leading to enhanced innate cytoprotective features by attenuating damage and/or enhancing the response of "help" signals plays a pivotal role. Hypoxia-inducible factor-1α (HIF-1α), constitutively upregulated by HA (1 mo, 34°C), is a crucial transcription factor in this program, although its specific role is as yet unknown. By using a rat HA model, we studied the impact of disrupting HIF-1α transcriptional activation [HIF-1α:HIF-1β dimeriz...
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 30, 2017 Category: Physiology Authors: Alexander-Shani, R., Mreisat, A., Smeir, E., Gerstenblith, G., Stern, M. D., Horowitz, M. Tags: Research Article Source Type: research

Exocytosis proteins as novel targets for diabetes prevention and/or remediation?
Diabetes remains one of the leading causes of morbidity and mortality worldwide, affecting an estimated 422 million adults. In the US, it is predicted that one in every three children born as of 2000 will suffer from diabetes in their lifetime. Type 2 diabetes results from combinatorial defects in pancreatic β-cell glucose-stimulated insulin secretion and in peripheral glucose uptake. Both processes, insulin secretion and glucose uptake, are mediated by exocytosis proteins, SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complexes, Sec1/Munc18 (SM), and double C2-domain protein B (DOC2B)....
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 30, 2017 Category: Physiology Authors: Aslamy, A., Thurmond, D. C. Tags: Review Source Type: research

Oscillation patterns are enhanced and firing threshold is lowered in medullary respiratory neuron discharges by threshold doses of a {mu}-opioid receptor agonist
In this study, effects of the μ-opioid receptor agonist fentanyl on spike train discharge properties of several different types of rhythm-modulating medullary respiratory neuron discharges were analyzed. Doses of fentanyl that were just sufficient for prolongation of discharges and slowing of the three-phase respiratory rhythm also produced pronounced enhancement of spike train properties. Oscillation and burst patterns detected by autocorrelation measurements were greatly enhanced, and interspike intervals were prolonged. Spike train properties under control conditions and after fentanyl were uniform within each experi...
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 1, 2017 Category: Physiology Authors: Lalley, P. M., Mifflin, S. W. Tags: Research Article Source Type: research

Cough and expiration reflexes elicited by inhaled irritant gases are intensified in ovalbumin-sensitized mice
In conclusion, Ova sensitization caused distinct and lingering increases in baseline cough frequency, and also intensified both CR and ER responses to inhaled irritant gases, which probably resulted from an allergic inflammation-induced hypersensitivity of airway sensory nerves. (Source: AJP: Regulatory, Integrative and Comparative Physiology)
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 1, 2017 Category: Physiology Authors: Zhang, C., Lin, R.-L., Hong, J., Khosravi, M., Lee, L.-Y. Tags: Research Article Source Type: research

Rest interval duration does not influence adaptations in acid/base transport proteins following 10 wk of sprint-interval training in active women
The removal of protons (H+) produced during intense exercise is important for skeletal muscle function, yet it remains unclear how best to structure exercise training to improve muscle pH regulation. We investigated whether 4 wk of work-matched sprint-interval trining (SIT), performed 3 days/wk, with either 1 (Rest-1; n = 7) or 5 (Rest-5; n = 7) min of rest between sprints, influenced adaptations in acid/base transport protein content, nonbicarbonate muscle buffer capacity (βmin vitro), and exercise capacity in active women. Following 1 wk of posttesting, comprising a biopsy, a repeated-sprint ability (RSA) test, and ...
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 1, 2017 Category: Physiology Authors: McGinley, C., Bishop, D. J. Tags: Research Article Source Type: research

Dietary nitrate does not reduce oxygen cost of exercise or improve muscle mitochondrial function in patients with mitochondrial myopathy
Muscle weakness and exercise intolerance negatively affect the quality of life of patients with mitochondrial myopathy. Short-term dietary nitrate supplementation has been shown to improve exercise performance and reduce oxygen cost of exercise in healthy humans and trained athletes. We investigated whether 1 wk of dietary inorganic nitrate supplementation decreases the oxygen cost of exercise and improves mitochondrial function in patients with mitochondrial myopathy. Ten patients with mitochondrial myopathy (40 ± 5 yr, maximal whole body oxygen uptake = 21.2 ± 3.2 ml·min–1·kg body wt&nda...
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 1, 2017 Category: Physiology Authors: Nabben, M., Schmitz, J. P. J., Ciapaite, J., le Clercq, C. M. P., van Riel, N. A., Haak, H. R., Nicolay, K., de Coo, I. F. M., Smeets, H., Praet, S. F., van Loon, L. J., Prompers, J. J. Tags: Research Article Source Type: research

Folic acid supplementation increases cutaneous vasodilator sensitivity to sympathetic nerve activity in older adults
During heat stress, blunted increases in skin sympathetic nervous system activity (SSNA) and reductions in end-organ vascular responsiveness contribute to the age-related reduction in reflex cutaneous vasodilation. In older adults, folic acid supplementation improves the cutaneous vascular conductance (CVC) response to passive heating; however, the influence of folic acid supplementation on SSNA:CVC transduction is unknown. Fourteen older adults (66 ± 1 yr, 8 male/6 female) ingested folic acid (5 mg/day) or placebo for 6 wk in a randomized, double-blind, crossover design. In protocol 1, esophageal temperature (Tes) ...
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 1, 2017 Category: Physiology Authors: Stanhewicz, A. E., Greaney, J. L., Alexander, L. M., Kenney, W. L. Tags: Research Article Source Type: research

Subfunctionalization of COX4 paralogs in fish
Cytochrome c oxidase (COX) subunit 4 has two paralogs in most vertebrates. The mammalian COX4-2 gene is hypoxia responsive, and the protein has a disrupted ATP-binding site that confers kinetic properties on COX that distinguish it from COX4-1. The structure-function of COX4-2 orthologs in other vertebrates remains uncertain. Phylogenetic analyses suggest the two paralogs arose in basal vertebrates, but COX4-2 orthologs diverged faster than COX4-1 orthologs. COX4-1/4-2 protein levels in tilapia tracked mRNA levels across tissues, and did not change in hypoxia, arguing against a role for differential post-translational regu...
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 1, 2017 Category: Physiology Authors: Porplycia, D., Lau, G. Y., McDonald, J., Chen, Z., Richards, J. G., Moyes, C. D. Tags: Research Article Source Type: research

Exposure to placental ischemia impairs postpartum maternal renal and cardiac function in rats
Women with a history of preeclampsia (PE) have an increased risk to develop cardiovascular and renal diseases later in life, but the mechanisms underlying this effect are unknown. In rats, we assessed whether placental ischemia results in long-term effects on the maternal cardiovascular and renal systems using the reduced uterine perfusion pressure (RUPP) model for PE. Sprague-Dawley rats received either a Sham or RUPP operation at gestational day 14. The rats were followed for 8 wk after delivery (Sham n = 12, RUPP n = 21) at which time mean arterial pressure (MAP; conscious), 24-h albuminuria, glomerular filtration rate ...
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 1, 2017 Category: Physiology Authors: Paauw, N. D., Joles, J. A., Spradley, F. T., Bakrania, B., Zsengeller, Z. K., Franx, A., Verhaar, M. C., Granger, J. P., Lely, A. T. Tags: Research Article Source Type: research

Exogenous amino acids suppress glucose oxidation and potentiate hepatic glucose production in late gestation fetal sheep
Acute amino acid (AA) infusion increases AA oxidation rates in normal late gestation fetal sheep. Because the fetal oxygen consumption rate does not change with increased AA oxidation, we hypothesized that AA infusion would suppress glucose oxidation pathways and that the additional carbon supply from AA would activate hepatic glucose production. To test this, late gestation fetal sheep were infused intravenously for 3 h with saline or exogenous AA (AA). Glucose tracer metabolic studies were performed and skeletal muscle and liver tissues samples were collected. AA infusion increased fetal arterial plasma branched chain AA...
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 1, 2017 Category: Physiology Authors: Brown, L. D., Kohn, J. R., Rozance, P. J., Hay, W. W., Wesolowski, S. R. Tags: Research Article Source Type: research

Moderate and sustained exercise modulates muscle proteolytic and myogenic markers in gilthead sea bream (Sparus aurata)
Swimming activity primarily accelerates growth in fish by increasing protein synthesis and energy efficiency. The role of muscle in this process is remarkable and especially important in teleosts, where muscle represents a high percentage of body weight and because many fish species present continuous growth. The aim of this work was to characterize the effects of 5 wk of moderate and sustained swimming in gene and protein expression of myogenic regulatory factors, proliferation markers, and proteolytic molecules in two muscle regions (anterior and caudal) of gilthead sea bream fingerlings. Western blot results showed an i...
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 1, 2017 Category: Physiology Authors: Velez, E. J., Azizi, S., Lutfi, E., Capilla, E., Moya, A., Navarro, I., Fernandez-Borras, J., Blasco, J., Gutierrez, J. Tags: Research Article Source Type: research

Effect of hypohydration on postsynaptic cutaneous vasodilation and sweating in healthy men
In conclusion, hypohydration attenuated endothelium-dependent CVC but did not affect endothelium-independent CVC or LSR responses. These data suggest that reductions in skin blood flow accompanying hypohydration can be partially attributed to altered postsynaptic function. (Source: AJP: Regulatory, Integrative and Comparative Physiology)
Source: AJP: Regulatory, Integrative and Comparative Physiology - May 1, 2017 Category: Physiology Authors: Tucker, M. A., Six, A., Moyen, N. E., Satterfield, A. Z., Ganio, M. S. Tags: Research Article Source Type: research