Prostaglandin levels and renin activity in renal venous blood of patients with renal hypertension.

In view of the possible role of prostaglandins /PG/ in the pathogenesis of hypertension we have determined PGE2 and PGF2 alpha levels simultaneously with plasma renin activity/PRA/ in renal venous and caval venous blood in 13 patients with unilateral renal artery stenosis/RAS/ and in six untreated patients with unilateral parenchymal renal disease/PRD/. Four patients with essential hypertension were the control group. PG levels and PRA were estimated by RIA. In patients with RAS the mean PGE2 level as well as PRA was higher on the side of the stenosis. No such difference was found in the PGF2 alpha level. There was a significant correlation between the renal vein PGE2 ratio and renin ratio /stenotic side versus contralateral side/ r=0.520, 0.02 less than p less than 0.05. In patients with PRD prostaglandin levels in venous blood of the affected kidney were similar to that of venous caval blood, but markedly elevated in the venous blood of the contralateral kidney. PRA was similar on both sides. The data obtained in this study indicate, that prostaglandins in renal venous blood behave differently in hypertensive patients with RAS and PRD. In patients with RAS augmented PGE2 release may serve as a protective mechanism. In patients with PRD, the increased PG level in the non-affected kidney may reflect a compensatory mechanism in spite of the atrophic process in the affected kidney.