Effects of the benzazepine SCH 23390 on prolactin release from isolated pituitary.

The benzazepine, SCH 23390 (10(-5) M), is able to block D2 anterior pituitary receptors and their interaction with a maximal concentration of dopamine (10(-7) M) in an experimental setting involving superfused pituitary slices and prolactin release by lactotrophs as a functional model of such receptors; this finding which correlates nicely with binding studies and drug-induced hyperprolactinaemia supports a SCH 23390 D1 dose-related selectivity; given at doses higher than those inducing behavioural changes, the compound may affect D2 receptor-driven functions, e.g. prolactin secretion.