CHLORPROMAZINE STIMULATION AND L-DOPA SUPPRESSION OF PLASMA PROLACTIN IN MAN1

Abstract

Plasma prolactin has been found to be elevated acutely following a single intramuscular injection of chlorpromazine in all of twelve endocrinologically normal subjects and in one patient with isolated growth hormone deficiency. The peak response occurs 1 to 2 hours following chlorpromazine injection. Two patients with panhypopituitarism showed no response. Pretreatment with L-dopa in normal subjects markedly inhibited the prolactin rise after chlorpromazine. In four patients with chronically elevated plasma prolactin, a single oral dose of L-dopa produced rapid lowering of the prolactin levels. These methods are suggested as useful, tests of pituitary function.