Previously, intravenous injection of 17beta-estradiol in decerebrate male cats was found to attenuate central command but not the exercise pressor reflex. This latter finding was surprising because the dorsal horn, the spinal site receiving synaptic input from thin-fiber muscle afferents, is known to contain estrogen receptors. We were prompted, therefore, to reexamine this issue. Instead of injecting 17beta-estradiol intravenously, we applied it topically to the L(7) and S(1) spinal cord of male decerebrate cats. We found that topical application (150-200 micro l) of 17beta-estradiol in concentrations of 0.01, 0.1, and 1 micro g/ml had no effect on the exercise pressor reflex, whereas a concentration of 10 micro g/ml attenuated the reflex. We conclude that, in male cats, estrogen can only attenuate the exercise pressor reflex in concentrations that exceed the physiological level.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1152/japplphysiol.00825.2002 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Abnormal cardiovascular control during exercise: Role of insulin resistance in the brain.
Auton Neurosci
January 2025
Departments of Applied Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Electronic address:
During exercise circulatory adjustments to meet oxygen demands are mediated by multiple autonomic mechanisms, the skeletal muscle exercise pressor reflex (EPR), the baroreflex (BR), and by feedforward signals from central command neurons in higher brain centers. Insulin resistance in peripheral tissues includes sensitization of skeletal muscle afferents by hyperinsulinemia which is in part responsible for the abnormally heightened EPR function observed in diabetic animal models and patients. However, the role of insulin signaling within the central nervous system (CNS) is receiving increased attention as a potential therapeutic intervention in diseases with underlying insulin resistance.
View Article and Find Full Text PDFDifferent effects of mechano- and metaboreflex on the central blood pressure waveform.
Front Physiol
January 2025
Faculty of Sport Sciences, Waseda University, Tokorozawa, Japan.
Introduction: The effect of mechanoreflex on central blood pressure (BP) is unclear, although the influence of metaboreflex has been investigated. A relatively small contribution of the mechanoreflex to the pressor response to exercise has been considered in humans because many studies have failed to isolate the mechanoreflex-mediated pressor response. In a recent study, we successfully isolated a mechanoreflex-mediated pressor response using static passive stretching (SPS) in the forearm.
View Article and Find Full Text PDFTwo-week Paramedic Hospital Training Augments Blood Pressure Response to Isometric Handgrip Exercise in Healthy Young Men.
Am J Physiol Regul Integr Comp Physiol
January 2025
College of Life and Health Sciences, Chubu University, Kasugai, Japan.
Persistent stressful situations can have detrimental cardiovascular effects; however, effects on the blood pressure (BP) response to exercise have not been fully examined. This study investigated the impact of a 2-week stressful situation on the exercise pressor response. Eight healthy male university paramedic trainees underwent a 2-week paramedic hospital training and a control period study.
View Article and Find Full Text PDFResting beat-to-beat blood pressure variability in humans: role of alpha-1 adrenergic receptors.
Clin Auton Res
January 2025
Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana, USA.
Purpose: Resting beat-to-beat blood pressure variability is a strong predictor of cardiovascular events and mortality. However, its underlying mechanisms remain incompletely understood. Given that the sympathetic nervous system plays a pivotal role in cardiovascular regulation, we hypothesized that alpha-1 adrenergic receptors (the main sympathetic receptor controlling peripheral vasoconstriction) may contribute to resting beat-to-beat blood pressure variability.
View Article and Find Full Text PDFSleep Deprivation Elevates Resting and Exercise Blood Pressures and Augments Pressor Response at Exercise Onset.
Med Sci Sports Exerc
December 2024
College of Life and Health Sciences, Chubu University, Kasugai, Aichi, JAPAN.
Purpose: Sleep deprivation and elevated blood pressure (BP) increase the risk of cardiovascular diseases. However, the effects of sleep deprivation on BP response, especially at exercise onset remain unclear. We aimed to elucidate the effects of experimental sleep deprivation (ESD) on resting and exercise BPs, including that at exercise onset, and investigate whether a night-time nap during ESD changes the ESD-altered BP.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!