Journal of Applied Physiology, Vol 45, Issue 3 403-407, Copyright © 1978 by American Physiological Society
Effects of angiotensin antagonism at rest and during exercise in sodium-deplete man
R. Fagard, A. Amery, T. Reybrouck, P. Lijnen, L. Billiet, M. Bogaert, E. Moerman and A. De Schaepdryver
Mean intra-arterial pressure (P-), heart rate (HR), cardiac index (CI),
total peripheral resistance index (TPRI), and plasma renin activity (PRA),
norepinephrine (PNE), and epinephrine (PE) were estimated in five normal
male subjects placed on a low-sodium diet for the previous 7 days. Subjects
were studied during rest in recumbency and during intravenous infusion of
either glucose or saralasin in a) recumbent position, b) sitting position
on the bicycle ergometer, and c) during submaximal graded exercise. At rest
recumbent saralasin induced pressure changes that were closely related to
logPRA. During exercise the increase in P- was significantly lower during
saralasin as compared to glucose from 110 W on, related to a greater
reduction in TPRI. The increase of PRA during exercise was about three
times greater with saralasin as compared to glucose, but the rises in PNE
and PE were similar in both series of tests. Angiotensin II may thus have a
role in the maintenance of P- in the supine sodium-deplete normal subjects,
and stimulation of the renin angiotensin system during physical exercise
contributes to a minor extent to the increase in P- in these conditions.
