A stop flow analysis of the effects of intrarenal infusion of bradykinin.

ABSTRACT

The effects of bradykinin (Bk) on renal function were investigated in the in situ dog kidney by means of the stop-flow method. Bradykinin, when injected into the renal artery of the dog, reduced the proximal reabsorption of sodium and water and decreased the secretion of p-aminohippuric acid (PAH). Because filtration was stopped during the experiments, there was no alteration of the peritubular colloid osmotic pressure, and geometric changes of the tubules were minimized. This enabled us to conclude that Bk decreased the transport efficiency of sodium and PAH. The demonstration of the inhibitory effects of Bk on PAH secretion suggests that the inhibition of acid secretion is dependent not only upon the increase in medullary blood flow, but also upon a reduction of the cortical clearance of PAH.