Effect of cyclic adenosine monophosphate on renal function and renin secretion.

The effect of cAMP, infused into the renal artery, on renal function and on the release of renin was studied in dogs displaying a normal serum Na level. Intrarenal infusion of 1 mg per kg per minute of cAMP caused a significant increase in RBF, dilatation of the efferent arterioles, the redistribution of renal blood flow and a significant increase in tubular Na-reabsorption. The antidiuretic action of cAMP is due partly to a hemodynamic and partly to a direct tubular effect. Decreased renin secretion was explained by the Na-load on the macula densa segment, being decreased by the intrarenal shifting of renal blood flow and with an eventual decomposition of cAMP.