Previous studies on renin release by an in vitro system of rat kidney slices, which is devoid of hemodynamic influences, have provided evidence that renin release is stimulated by a beta-adrenergic mechanism. We used this system to study effects of tyramine (an indirectly acting amine capable of displacing endogenous catecholmines from sympathetic nerve endings) on renin release. Tyramine (10(-3)M) in the presence of a monoamine oxidase inhibitor (pheniprazine, 10(-5)M) and a phosphodiesterase inhibitor (theophylline, 10(-3)M) significantly (P less than 0.01) stimulated renin release when values were compared to control observations for media containing only the inhibitors. Tyramine-induced stimulation of renin release was blocked by the beta-blocking agent, propranolol (2 X 10(-4) M), and the neural uptake blocking agent, cocaine (10(-5) M), but not by the alpha-antagonist, phentolamine (9 X 10(-4) M). These observations demonstrate a potential role for the sympathetic innervation of the juxtaglomerular apparatus on renin release.