American Journal of Physiology. 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.

Muscle metaboreflex stimulates the cardiac sympathetic afferent reflex causing positive-feedback amplification of sympathetic activity: effect of heart failure
Am J Physiol Regul Integr Comp Physiol. 2023 Nov 27. doi: 10.1152/ajpregu.00235.2023. Online ahead of print.ABSTRACTExercise intolerance is a hallmark symptom of heart failure and to a large extent stems from reductions in cardiac output that occur due to the inherent ventricular dysfunction coupled with enhanced muscle metaboreflex-induced functional coronary vasoconstriction which limits increases in coronary blood flow. This creates a further mismatch between O2 delivery and O2 demand which may activate the Cardiac Sympathetic Afferent Reflex (CSAR) causing amplification of the already increased sympathetic activity in ...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - November 27, 2023 Category: Physiology Authors: Joseph Mannozzi Danielle Senador Jasdeep Kaur Matthew Gross Megan McNitt Alberto Alvarez Beruk Lessanework Donal S O'Leary Source Type: research

Relationship between red blood cell lifespan and endogenous carbon monoxide in the common bottlenose dolphin and beluga
Am J Physiol Regul Integr Comp Physiol. 2023 Nov 20. doi: 10.1152/ajpregu.00172.2023. Online ahead of print.ABSTRACTCertain deep-diving marine mammals (i.e., northern elephant seal (Mirounga angustirosis), Weddell seal (Leptonychotes weddellii)) have blood carbon monoxide (CO) levels that are comparable to those of chronic cigarette smokers. Most CO produced in humans is a by-product of heme degradation, which is released when red blood cells (RBC) are destroyed. Elevated CO can occur in humans when RBC lifespan decreases. The contribution of RBC turnover to CO concentrations in marine mammals is unknown. Here, we report t...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - November 20, 2023 Category: Physiology Authors: Anna B Pearson Luis A H ückstädt Stephen T Kinsey Todd L Schmitt Todd R Robeck Judy St Leger Paul J Ponganis Michael S Tift Source Type: research

Impact of Maternal Obesity on Resting Muscle Sympathetic Nerve Activity during Uncomplicated Pregnancy: A Longitudinal Assessment
Am J Physiol Regul Integr Comp Physiol. 2023 Nov 13. doi: 10.1152/ajpregu.00098.2023. Online ahead of print.ABSTRACTMaternal obesity increases the risk of adverse pregnancy outcomes. The mechanisms that contribute to this elevated risk are unclear but may be related to greater activity of the sympathetic nervous system, which is associated with hypertensive disorders of pregnancy. We hypothesized that resting muscle sympathetic nerve activity (MSNA) would be greater in women with obesity during pregnancy when compared with normal-weight women. Blood pressure, heart rate and MSNA were recorded during 5 min of supine rest in...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - November 13, 2023 Category: Physiology Authors: Sarah L Hissen Ryosuke Takeda Mark B Badrov Sonia Arias-Franklin Shivani Patel David B Nelson Tony G Babb Qi Fu Source Type: research

The intensity-dependent effects of exercise and superimposing environmental heat stress on autophagy in peripheral blood mononuclear cells from older men
Am J Physiol Regul Integr Comp Physiol. 2023 Nov 13. doi: 10.1152/ajpregu.00163.2023. Online ahead of print.ABSTRACTAutophagy is a vital cellular process, essential to maintaining cellular function during acute physiological stressors including exercise and heat stress. We previously showed that autophagy occurs during exercise in an intensity-dependent manner in peripheral blood mononuclear cells (PBMCs) from young men, with elevated responses in the heat. However, given autophagy declines with age, it is unclear whether a similar pattern of response occurs in older adults. Therefore, we evaluated autophagy and the cellul...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - November 13, 2023 Category: Physiology Authors: James J McCormick Morgan K McManus Kelli E King Nicholas Goulet Glen P Kenny Source Type: research

Post-contraction [Acetylcarnitine] Reflects Inter-individual Variation in Skeletal Muscle ATP Production Patterns < em > in Vivo < /em >
Am J Physiol Regul Integr Comp Physiol. 2023 Nov 13. doi: 10.1152/ajpregu.00027.2023. Online ahead of print.ABSTRACTIn addition to its role in substrate selection (carbohydrate vs. fat) for oxidative metabolism in muscle, acetylcarnitine production may be an important modulator of the energetic pathway by which ATP is produced. A combination of noninvasive magnetic resonance spectroscopy measures of cytosolic acetylcarnitine and ATP production pathways was used to investigate the link between [acetylcarnitine] and energy production in vivo. Intracellular metabolites were measured in the vastus lateralis muscle of 8 males (...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - November 13, 2023 Category: Physiology Authors: Christopher M T Hayden Rajakumar Nagarajan Zoe H Smith Samantha Gilmore Jane A Kent Source Type: research

Dose-dependent non-thermal modulation of whole-body heat exchange during dynamic exercise in humans
Am J Physiol Regul Integr Comp Physiol. 2023 Nov 13. doi: 10.1152/ajpregu.00203.2023. Online ahead of print.ABSTRACTTo maintain heat balance during exercise, humans rely on skin blood flow and sweating to facilitate whole-body dry and evaporative heat exchange. These responses are modulated by the rise in body temperature (thermal factors), as well as several non-thermal factors implicated in the cardiovascular response to exercise (i.e., central command, mechanoreceptors, metaboreceptors). However, the way these non-thermal factors interact with thermal factors to maintain heat balance remains poorly understood. We theref...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - November 13, 2023 Category: Physiology Authors: Sean R Notley Ashley P Akerman Andrew W D'Souza Robert D Meade Emma R McCourt James J McCormick Glen P Kenny Source Type: research