The effect of neuroleptic drugs on drinking induced by central administration of angiotensin or carbachol.

The effect of a series of neuroleptic drugs on the drinking response elicited by intracerebroventricular injection of either angiotensin or carbachol into conscious rats was studied. The i.p. injection of haloperidol, cis-flupenthixol, or fluphenazine antagonized both angiotensin-induced and carbachol-induced drinking. When injected into the lateral ventricles, the neuroleptics haloperidol, fluphenazine, cis-fluphenthixol and sulpiride were potent inhibitors of angiotensin-induced drinking, but had little effect on the dipsogenic action of carbachol. Clozapine, administered centrally, antagonized drinking caused by both angiotensin and carbachol. Pimozide and chlorpromazine were also potent inhibitors of angiotensin-induced drinking, while trans-flupenthixol was inactive. Our results support the concept of an involvement of dopamine in angiotensin-induced drinking.