Central sympathetic reactivity inhibited by indoramin.

The action of indoramin on central autonomic activity was investigated using the sympathetic-cholinergic electrodermal response system. Indoramin (0.33-10 mg/kg, i.v.) significantly reduced the amplitude of electrodermal responses (EDR) evoked by stimulation of the hypothalamus in a dose-related manner. The CNS effects of indoramin on the EDR were partially antagonized by yohombine pretreatment. These results demonstrate that indoramin reduces central sympathetic reactivity and suggest that an alpha-adrenergic inhibitory mechanism may be involved.