Desipramine blocks stress-induced prolactin release in rats: role of central beta-2 adrenoceptors

ABSTRACT

The present study was designed to examine the relationship between beta-adrenoceptors and the enhanced, sustained prolactin secretion induced by immobilization stress in rats. Chronic administration of desipramine (15 mg kg**-1 day**-1, intraperitoneally) for 7 days, a procedure that desensitizes central beta-adrenoceptors, partially inhibits stress-induced prolactin release. Intracerebroventricular adminsitration of the beta-2 adrenoceptor agonist salbutamol (1 microng/rat) to rats pretreated with desipramine for 7 days, 15 min before immobilization, significantly relieved the inhibition by desipramine 5 and 10 min after the initiation of stress but the effect was not demonstrable after 20 and 40 min. We conclude that beta-2 adrenoceptors play a role in the control prolactin release in response to stress