PRL and hyperprolactinemia: In terms of ALD, since acute and repeated alcohol ingestions sharply rise plasma prolactin levels and decrease plasma testosterone levels in male volunteers (139) and ethanol induces hyperprolactinemia lactotrope growth in female rats (140), it is speculated that increased prolactin is an endogenous protective mechanism to alleviated injury of the liver, and possibly other ethanol-targeted tissues, via unknown pathways.