Inhibition of renin secretion by systemic and intrarenal angiotensin infusion.

BLAIR-WEST, J. R., J. I? COGHLAN, D. A. DENTON, J. W. FUNDER, B. A. SCOGGINS, AND R. D. WRIGHT. Inhibition of renin secretion by systemic and intrarenal angiotensin infusion. Am. J. Physiol. 220(5): 1309-1315. 197 1 .-Conscious sheep were allowed to become sodium depleted by loss of parotid saliva for 24 or 48 hr. Angiotensin II was infused continuously intravenously at 10, 20, or 60 pg/hr or into the renal artery at 3 or 6 pg/hr during a 24-hr control period and throughout the period of sodium depletion. Intravenous infusion of angiotensin II prevented the usual increase of plasma renin concentration (PRC) during the first 24 hr of sodium loss and blunted the PRC response over the next 24 hr. When the infusion was stopped, PRC increased within 2 hr to high levels. Continuous intrarenal infusion of angiotensin II caused similar inhibition of PRC rise during 24 hr of sodium depletion without effect on systemic blood angiotensin II concentration, systemic blood pressure, plasma [K], or renal sodium excretion. It is concluded that the inhibition of renin release during sodium depletion was due to a direct intrarenal action of angiotensin II at physiological concentration in blood. Renin secretion may be regulated partly by a short-loop negative feedback mechanism.