Renal-portal shunt to restore normal reninism and blood pressure in experimental renovascular hypertension in dogs.

The role of the liver in the metabolism of renin was evaluated in dogs with high plasma renin and hypertension due to experimental bilateral renal artery stenosis. Ten adult dogs were studied in three consecutive phases: (1) basal conditions, (2) with bilateral ischemic kidneys, and (3) after derivation of renal vein blood into the portal system. Secretion, total clearance, hepatic clearance, and hapatic extraction of renin were estimated in each phase by measuring plasma renin activity (PRA) in blood collected simultaneously from arteries, inferior vena cava, vena porta, hepatic and renal veins, and by determining renal and hepatic blood flow. Blood pressure was measured by intra-arterial catheterization. The results demonstrated an increase in the hepatic metabolism of renin when the hyper-reninemic patterns of renal blood directly perfused the liver. Under these conditions, hepatic and circulating renin fell to basal values and blood pressure returned to normal.