Effect of pimozide and sulpiride on the release of LH and FSH by pituitary cells in culture.

A culture of dispersed rat anterior pituitary cells was used to test the ability of pimozide and sulpiride to affect the basal gonadotropin release and their effects on the response to Gn-RH. Sulpiride did not alter either the basal or the Gn-RH-induced release of LH, and the lowest dose (500 ng/ml) seemed to potentiate the Gn-RH-induced FSH release. On the other hand, both doses of pimozide (100 ng/ml and 10 microgram/ml) significantly inhibited the release of FSH and LH induced by Gn-RH but did not affect the basal release of the two gonadotropins. From these results it is evident that pimozide, at the doses used, is a powerful inhibitor of the pituitary response to Gn-RH in vitro. Sulpiride on the other hand had no effect on the pituitary response to Gn-RH in vitro, except on FSH release, using the lower dose.