STRESSORS, INCLUDING SOCIAL-CONFLICT, DECREASE PLASMA PROLACTIN IN MALE GOLDEN-HAMSTERS

Following exposure to a stressor, plasma prolactin (PRL) rises in most species. The purpose of the present study was to examine the effect o f social conflict or of footshock stress on PRL responsiveness in male Syrian hamsters. Contrary to expectations, PRL was significantly lowe r in subordinate hamsters than in their dominant opponents or in contr ols following one, five, or nine exposures to social conflict. Similar ly, PRL was reduced in hamsters subjected to a mild footshock stressor . By contrast, adrenocorticotropin, another stress-responsive hormone, was elevated following exposure to each of these stressors. We also d emonstrate that PRL release is inhibited by dopamine as it is in other species by showing that there is a dose-dependent increase in PRL rel ease following treatment with the dopamine receptor blocker, domperido ne. (C) 1995 Academic Press, Inc.