Effect of L-Tryptophan on Growth Hormone and Prolactin Release in Normal Volunteers and Patients with Secretory Pituitary Tumors

Abstract

L-tryptophan (a serotonin precursor) 5 g. was administered to 20 normal volunteers (5 males, 10 females on no medications and 9 females on oral contraceptives). Fourteen patients with secretory pituitary tumors were similarly studied. The tumor group consisted of 8 patients with pure prolactin secreting tumors, 3 with pure growth hormone secreting tumors and 3 whose tumors secreted both GH and PRL.