Adrenergic Stimulation of Renin Secretion in the Isolated Perfused Rat Kidney

Abstract

To avoid complicating systemic effects, the influence of adrenergic hormones on renin secretion was examined in the isolated rat kidney perfused with Krebs-dextran solution at a constant mean pressure and flow rate. Isoproterenol and glucagon produced a consistent increase in renin secretion without a change in perfusion pressure and flow. Similarly the increase in renin secretion with norepinephrine, which was associated with intense vasoconstriction and raised perfusion pressure, was still observed after the vasoconstrictive effect was abolished with phenoxybenzamine. Isoproterenol- stimulated renin secretion, unaffected by phenoxybenzamine, was markedly suppressed by dl-propranolol but not by d-propranolol. The failure of dl-propranolol to suppress the renin response to glucagon confirms observations in other tissues and suggests involvement of other receptors or alternative mechanisms. These findings support a direct intrarenal effect of adrenergic hormones on renin secretion, and this effect may be mediated specifically by beta receptors in the case of catecholamines.