Decreased renin release and constant kallikrein secretion after injection of L-NAME in isolated perfused rat kidney.

A possible role of the endothelial L-arginine/NO pathway in the control of renal hemodynamics, renin release and kallikrein secretion was studied in an isolated rat kidney model perfused in a closed-circuit. NG-nitro-L-arginine methyl ester (L-NAME, 1-50 microM), an inhibitor of nitric oxide biosynthesis, caused a dose-dependent increase in perfusion pressure (PP) and a dose-dependent decrease in renal perfusate flow. Renin release was inhibited independently of a rise in PP. L-NAME did not change the urinary kallikrein secretion. These results confirm the intervention of the L-arginine/NO pathway in the vasodilation of this isolated perfused kidney model and demonstrate the inhibitory effect of L-NAME on renin release. They suggest that nitric oxide synthesis plays a role in stimulating renin release and is not involved in the regulation of urinary kallikrein secretion.