Failure of reserpine to block ether-induced release of prolactin: physiological evidence that stress induced prolactin release is not caused by acute inhibition of PIF secretion

Plasma prolactin levels in the rat are elevated by reserpine treatment. This effect has generally been attributed to the inhibition of the monoaminergic component of regulation of secretion of prolactin inhibiting factor (PIF). In this study we report that ether stress which produces prolactin release in normal rats was equally effective in stimulating prolactin release in reserpine treated animals whose initial baseline prolactin levels were elevated. These results indicate that the ether stress induced release of prolactin is not due to inhibition of the secretion of PIF, and are compatible with the view that a prolactin releasing substance mediates this acute secretory response.