Effect of substituted benzamides on the cAMP system in the hypothalamus and striatum of the rat.

Adenylate cyclase and phosphodiesterase activities were evaluated in the striatum and hypothalamus of male rats after single treatment with different substituted benzamides (sulpiride, sultopride, tiapride, metoclopramide and bromopride) or chlorpromazine. None of the benzamides modifies the adenylate cyclase activity in the striatum but all of them stimulate this activity in the hypothalamus. The stimulating effect on the adenylate cyclase activity exerted by the in vitro addition of dopamine is not modified by the previous treatment with benzamides. Phosphodiesterase activity is not modified in the striatum, whereas it is depressed in the hypothalamus and completely inhibits the in vitro stimulating effect of dopamine.