Aortic Baroreceptor Reflex Control of Blood Pressure: Effect of Fitness

• Main Author: Andresen, Jean M.
• Other Authors: Raven, Peter Bernard, 1940-
• Format: Others
• Language: English
• Published: University of North Texas 1992
• Subjects: blood pressure; aortic baroreceptor reflexes; endurance exercise training; Blood pressure > Regulation.; Physical fitness > Physiological aspects.
• Online Access: https://digital.library.unt.edu/ark:/67531/metadc500922/

Aortic baroreflex (ABR) control of blood pressure was examined in 7 untrained (UT) and 8 endurance exercise trained (EET) young men. ABR control of blood pressure was determined during a steady state phenylephrine infusion to increase mean arterial pressure 10-15 mmHg, combined with positive neck pressure to counteract the increased carotid sinus transmural pressure, and low levels of lower body negative pressure to counteract the increased central venous pressure. Functioning alone, the ABR was functionally adequate to control blood pressure. However, ABR control of HR was significantly diminished in the EET subjects due solely to the decrease in the ABR sensitivity. The persistent strain from an increased stroke volume resulting from endurance exercise training could be the responsible mechanism.