Chronic alcohol administration increases serum prolactin level and pituitary cell proliferation, and alters hypothalamus neurotransmitters in rat.

OBJECTIVES: Alcohol induces hyperprolactinemia in both alcoholic men and women, but the mechanism is not fully established. The aim is to investigate the mechanism involved in elevation of serum prolactin level after chronic alcohol administration.

METHODS: In this study, healthy female SD rats were given alcohol for 8 weeks and checked for serum prolactin level by radioimmunoassay. Interior pituitary cell proliferation was determined by immunohistochemistry score of Ki-67, and hypothalamic neurotransmitters were detected by Coulomb HPLC electrochemical array.

RESULTS: We demonstrated that serum prolactin level and wet pituitary weight of alcohol-fed rats were significantly increased. Interior pituitary cell proliferation was significantly enhanced; hypothalamic dopamine, 5-HT and GABA levels were reduced while glutamate level was increased by chronic alcohol administration; hypothalamic noradrenalin level remained unchanged.

CONCLUSION: Our study suggested that chronic alcohol administration resulted in elevated serum prolactin level in normal SD rats probably through enhancing pituitary gland cell proliferation combined with altered hypothalamic neurotransmitters that regulate prolactin level.