Inhibition of renin secretion by HCl is related to chloride in both dog and rat.

Abstract

To determine if inhibition of renin release by HCl is related to acidosis or to Cl-, the effects of peripheral venous infusions of HCl and H2SO4 on plasma renin activity (PRA) were compared in the dog and the rat. In NaCl-deprived, pentobarbital-anesthetized dogs, either 0.15 M HCl (n = 10) or 0.075 M H2SO4 (n = 7) was infused for 60 min. In 5 of the 10 HCl-infused dogs (group A), urine Cl- excretion increased (P less than 0.01) during HCl infusion. In the remaining five dogs (group B), Cl- excretion did not increase. Cl- excretion also did not increase during H2SO4 infusion. Comparable acidosis was produced in all three groups. PRA decreased (P less than 0.01) in response to HCl in group A but did not change (P greater than 0.8) in group B HCl-infused dogs or in H2SO4-infused dogs. In NaCl-deprived, anesthetized rats, PRA was suppressed (P less than 0.05) by HCl (from 40.6 +/- 9.4 to 27.4 +/- 5.3 ng . ml-1 . h-1 (SE)) but not H2SO4 (from 37.1 +/- 4.2 to 37.0 +/- 6.3 ng . ml-1 . h-1), despite comparable acidosis. Cl- excretion increased only in HCl-infused rats. In conclusion, inhibition of PRA by acute infusion of HCl is specifically related to Cl-.