Effect of Exercise Muscle Temperature on Renal and Sympathetic Responses to Isometric Exercise in Humans
Open Access
Author:
Kuipers, Nathan T.
Graduate Program:
Neuroscience
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
May 02, 2008
Committee Members:
Chester A Ray, Committee Chair/Co-Chair Lawrence Isaac Sinoway, Committee Member James Anthony Pawelczyk, Committee Member Thomas C Pritchard Iii, Committee Member
Keywords:
heat aging ACE-inhibition cool kidnet
Abstract:
The renal vasculature helps maintain blood pressure and cardiovascular function during exercise and thermal stress. During exercise, renal vascular function can be influenced by feedback from muscle afferents in the exercising limb. The influence of temperature on muscle afferent control of renal blood flow during exercise in humans is unknown. Therefore, to characterize the influence of muscle temperature on renal blood flow during exercise three studies were conducted: 1) the influence of muscle temperature on renal vascular responses to isometric exercise; 2) the interactive effect of aging and muscle heating on renal vascular responses to isometric exercise; and 3) the effect of ACE-inhibition on renal vascular responses to isometric exercise at hyperthermic muscle temperatures. Muscle heating and cooling increased and decreased renal vasoconstriction during isometric exercise, respectively. Second, compared to younger subjects, forearm heating augmented renal vasoconstriction during isometric exercise in older individuals. Third, ACE-inhibition did not alter renal vascular responses to isometric handgrip. Collectively, these findings indicate that muscle temperature and aging contribute importantly to renal vascular control during isometric exercise, but the renin-angiotensin and kallikrein-kinin systems do not.
