The effects of methoxyflurane and ether alone or in combination with apomorphine or 2 Br-α-ergocryptine (CB-154) on prolactin release in ovariectomized, estrogen-treated rats

Abstract

Continuous methoxyflurane (MF) anesthesia caused a temporary increase in plasma prolactin but abolished the afternoon prolactin surge in ovariectomized, estrogenized rats with aortic catheters. In the morning hours (0900–1200), prior to the prolactin surge, administration of Apomorphine HCl (APO) or CB-154 lowered plasma prolactin and MF did not alter these responses. Similarly, continuous ether anesthesia prior to the afternoon surge elevated plasma prolactin but did not override the suppressive effects of APO and only partially overrode those of CB-154. It is suggested that the sharp and immediate increases in plasma prolactin produced by MF and ether are due to involvement of the dopamine/PIF system since two different dopaminergic receptor stimulators blocked the response.