The Renin-Angiotensin System and Renal Prostaglandin E 2 Release in Dogs

Abstract

Abstract

The relationship between renin and renal prostaglandin E₂ (PGE₂) release was investigated in anesthetized dogs using a highly specific radioimmunoassay for PGE₂ measurement. There was a dissociation between the acute inhibition of renin release with intra-renal infusion of angiotension II (AII) or angiotensin III (AIII) and renal PGE, release. Intrarenal infusion of norepinephrine resulted in a significant increase both in renin and renal PGE₂ release. Intrarenal infusion of bradykinin increased renal PGE₂ but not renin release, and infusion of isoproterenol increased renin release but not renal PGE₂ release. Renal pressure reduction from 134 to 71 mm Hg increased renin release while the renal PGE₂ release was unaltered. In addition, renal vasoconstriction was observed with an infusion of norepinephrine, AII, and AIII, while renal vasodilation was observed with an infusion of isoproterenol and bradykinin, and renal pressure reduction. Neither renal vasoconstriction nor vasodilation, however, correlated with renal PGE₂ release. These results suggest that the renin-angiotensin system probably does not play a regulatory role in the control of renal PGE₂ release, and that the change of renal vascular tone does not accompany renal PGE₂ release.