Intravenous infusion of β-endorphin increases serum prolactin, but not growth hormone or cortisol, in depressed subjects and withdrawing methadone addicts

Abstract

In a randomized, double blind, cross-over study, human β-endorphin or saline was infused iv over 30 min into six depressed psychiatric patients and four methadone addicts. All depressed subjects showed prompt, 2-to 4-fold increases in serum PRL levels, which lasted at least 2 h. The addicts, who were undergoing acute methadone withdrawal, showed similar PRL increases, which were dose dependent. β-Endorphin did not increase serum levels of cortisol or GH in either group of subjects. These results suggest that iv β-endorphin has potent but selective neuroendocrine effects in depressed patients and subjects withdrawing from methadone. © 1980 by The Endocrine Society.