Abstract
The influence of amineptine, an antidepressant currently employed having mainly selective dopaminergic neurochemical activity, on the pressor responses evoked by norepinephrine (NE) and dopamine (DA) was studied in anesthetized whole rats. Amineptine at doses of 0.5, 1.5, and 5.0 mg/kg/30 min infused into the femoral vein of the rat caused a dose-related inhibition of the pressor responses of NE and DA. The hypertensive responses of NE and DA augmented by pretreatment with reserpine, a catecholamine depletor, were also clearly depressed following the infusion of amineptine with a rate of 1.5 mg/kg/30 min. Furthermore, the pressor responses of NE and DA potentiated by pretreatment with debrisoquin, a sympathetic neuron blocker, were markedly diminished after pretreatment with the infusion of amineptine at the above same rate (1.5 mg/kg/30 min). These experimental results demonstrate that amineptine causes an inhibitory effect on the pressor responses evoked by NE and DA. It is thought that the amineptine effect may be due to the blockade of the peripheral adrenergic alpha-receptors in addition to the previously described uptake inhibition of dopamine.