Effect of Perphenazine on the Secretion of Prolactin in Vivo and in Vitro 1

Summary

Injection (iv) of perphenazine, an antipsychotic tranquilizer, into rats produces a 10–fold increase in plasma prolactin levels as measured by radioimmunoassay; a similar response is seen when using adult male or female rats; plasma prolactin levels are increased significantly by 10 min post–injection and a maximal response occurs after 30 min. Ten micrograms of perphenazine is the minimal active dose that will cause an elevation in plasma prolactin levels. Addition of up to 10 μg/ml medium of perphenazine to in vitro cultures of enzymatically dispersed rat pituitary cells does not stimulate secretion of prolactin. Also (ip) injection of 1 mg perphenazine into rats bearing 2 pituitary transplants under the kidney capsule, causes only a marginal increase in prolactin secretion. These data indicate that perphenazine releases prolactin by acting on brain centers above the level of the pituitary.