Estrogen Potentiation of Phenothiazine-Induced Prolactin Secretion in Man

Abstract

In order to evaluate the effects of estrogen on stimulated prolactin secretion in man, 8 mg perphenazine (Trilafon®) was administered orally to 4 groups of subjects: normal men and normal women with and without prior exogenous estrogen treatment. Radioimmunoassayable serum prolactin rose from 7 ± 1 ng/ml (1 se) to a mean maximum of 21 ± 6 ng/ml in 6 normal male subjects before estrogen administration and from 8 ± 2 to 37 ± 6 ng/ml after estrogen administration; serum prolactin increased from 7 ± 2 to 41 ± 7 ng/ml in 4 normal women and from 10 ± 1 to 112 ± 11 ng/ml in 6 women on exogenous estrogens. Although baseline prolactin values were similar in the 4 groups of subjects, we observed that 1) perphenazine-induced prolactin secretion was greater in women than in men and 2) perphenazine-stimulated prolactin secretion was augmented in men and women by prior estrogen administration. We conclude that estrogens may play an important role in the regulation of prolactin secretion in man.