RU486对早孕妇女蜕膜组织级体激素受体含量及血清激素水平的影响

THE EFFECT OF RU486 ON HUMAN DECIDUAL STEROID RECEPTORS AND SERUM HORMONE LEVELS IN EARLY PREGNANCY

RU486是法国Roussel Uclaf公司合成的一种孕酮受体水平拮抗剂,临床实践证明该化合物具有较好的催经止孕效果。为进一步明确RU486的作用机理,本文测定了早孕妇女服用RU486后蜕膜组织孕、雌激素受体含量及血清激素水平。结果表明,一次口服RU486 600mg可使早孕5—7周妇女蜕膜组织细胞核内孕、雌激素受体含量增加,细胞浆内孕激素受体含量减少,血清雌二醇(E_2)、睾酮(T)含量上升而对FSH、HCG和孕酮(P)含量无明显影响。本研究结果进一步证实,大剂量的抗孕激素RU486能竞争性地结合蜕膜组织孕激素受体,使早孕期高浓度的内源性孕酮与其受体的正常结合受到干扰,从而达到抗早孕目的。

RU486 is an antiprogesterone acting at progesterone receptorlevel. Clinical trials showed that it could satisfactorily interrupt earlyhuman pregnancy when used in combination with prostaglandins. The mainpurpose of this study was to investigate the mechanism of RU486 on humanearly decidua. The decidual PR and ER concentrations and hormone levelsof women with 5-7 weeks gestation were measured by DCC method and RIAbefore and after RU486 (600mg ) administration. The results indicatedthat RU486 could significantly increased the decidual PnR and EnR conce-ntration and decrease the PcR concentration, while the serum estradiol andtestosterone levels were enhanced, the FSH, HCG and progesterone levelswere unaffected. The effect of RU486 on the above mentioned parameterswas not changed during 36-60 hours after drug intake. Our study suggestedthat the early pregnancy interrupted effect of RU486 may not act throughthe hypothalamus-pituitary-ovary axis but act by a direct effect on humandecidual PR. The antagonistic effect of RU486 againsted progesterone onPR and ER synthesis increased the amount of PnR and EnR. The highaffinity and prolonged combination of RU486 and PnR interrupt the effectof progesterone on the maintainance of decidua. The cause of increasedestradiol and testosterone levels after RU486 administration is not clear.It might be related to the antiglucocorticoid effect of RU486.