高催乳素血症对大鼠性激素的正反馈作用的影响

THE POSITIVE FEEDBACK ACTION OF STEROIDS IN HYPERPROLACTINAEMIC RATS

高催乳素血症影响促性腺激素的分泌．其机制仍不清楚，本文描述了利用多巴胺阻断剂胃复安诱导慢性切卵巢大鼠处于高催乳素状态，观察高催乳素血症对雌激素预激后，孕酮诱导的LH、FSH峰的影响．慢性切卵巢大鼠持续皮下注射胃复安，对照组在同一时间注射生理盐水，每日二次，持续5天。两组动物同时给予雌二醇，72h后注射孕酮，血中LH水平在注射雌二醇后72h显著下降，两组无差异。对照组于注射孕酮5h后出现LH、FSH峰，而实验组孕酮未能诱导LH、FSH峰的出现．实验结果提示高催乳素血症可抑制性激素对促性腺激素的正反馈作用．

Hyperprolactinaemia affect the secretion of gonadotrophin, the mechanism is unknown. Hyperprolactinaemia was induced in ovariectomized rats with injection of dopamine antgonist Metoclopramide (MCP),the effect of hyperprolactinaemia on the progesterone-induced LH 、FSH surge occurs in oestrogen - primed, ovariectomized rats was delineated. The ovariectomized rats was given injections of MCP,Control animals were treated with 0. 9% NaCl twice daily. Treatment was continued for 5 days,all animals were treated with E2 and 72 hours after the administration of E2 they were treated with progesterone. 72 hours after E2 administration plasma LH levels were significantly reduced in both qroups marked surges LH. FSH occurs 5 hours after the progesterone administration in control groups. The surges of LH. FSH did not occur in hyperprolactinaemic rats. The present results demostrate that hyperprolactinaemia may abolish the positive feedback of progestrone in oestrogen -primed ovariectomized rat.