Dissociation between renal prostaglandin E2 and renin release. Effects of glucagon, dopamine and cyclic AMP in dogs.

To examine the relationship between prostaglandin E2 (PGE2) and renin release, glucagon, dopamine and dibutyryl cyclic AMP (DB-cAMP) were infused into dog kidneys during autoregulatory dilation of preglomerular vessels. Autoregulatory vasodilation, which enhances PGE2 and renin release, was induced by renal arterial constriction or ureteral occlusion. Glucagon infusion increased both PGE2 and renin release during autoregulatory vasodilation, and renin release was almost abolished after inhibiting PGE2 release by indomethacin. In contrast, dopamine and DB-cAMP infused during autoregulatory vasodilation increased renin release without significantly changing PGE2 release. Stimulation of renin release was not dependent on vasodilatory effects, which for all drugs were greatly diminished during autoregulatory vasodilation. Hence, glucagon stimulates both PGE2 and renin release. Most of the increase in renin release during glucagon infusion is prostaglandin-dependent since indomethacin greatly reduced the stimulatory effect. In contrast, dopamine and DB-cAMP stimulate renin release without increasing PGE2 release as previously found for beta-adrenergic stimulation.