[Double controlled regulation of renin release by the sympathetic nervous system. Stimulation via beta receptors and inhibition via alpha receptors].

The beta-sympathomimetic amine isoprenaline increases the plasma renin concentration by a stimulation of beta-receptors which control renin release. Isoprenaline also lowers systemic blood pressure and causes a reflex-mediated activation of the sympathetic nervous system. In these investigations it has been tested to see whether the catecholamines released by this activation modulate renin release by stimulation of certain alpha-receptors. Pretreatment of rats with reserpine or with the ganglionic blocking agent Trimethidinium enhanced the increase in plasma renin concentration induced by isoprenaline. So did pretreatment with the irreversible alpha-receptor antagonist phenoxybenzamine. Renal denervation also increased the effect of isoprenaline on plasma renin concentration. It is concluded that catecholamines released from the sympathetic nervous system can decrease renin secretion by an activation of certain alpha-receptors. The sympathetic nervous system may thus exert control of renin release by beta-receptors which stimulate and by alpha-receptors which diminish renin secretion.