米非司酮对离体大鼠垂体细胞促黄体激素分泌的影响及其机制  

EFFECT OF MIFEPRISTONE ON GONADOTROPIN SECRETION AND ITS MECHANISM IN CULTURED PITUITARY CELLS

作　　者：朱四军[1,2] 庄临之[1] 谢衷明[3] 徐一树[1] 赵白鸽[3] 

机构地区：[1]中国科学院动物研究所 [2]上海市计划生育科学研究所,上海200032 [3]上海市计划生育科学研究所

出　　处：《动物学报》2001年第4期412-418,共7页ACTA ZOOLOGICA SINICA

基　　金：中国科学院动物研究所计划生育生殖生物学国家重点实验室资助项目&&

摘　　要：本实验应用垂体细胞体外培养模型 ,观察了米非司酮 (MP)对GnRH、高浓度细胞外K+([K+]e)和蛋白激酶C激活剂PMA诱导的LH分泌的影响。结果证实MP可以剂量和时间依赖方式抑制GnRH诱导的LH分泌 ,并可拮抗P调节GnRH诱导的LH分泌效应。同时发现 10 -7mol/LMP短时间处理 4h能抑制 6 0mmol/LKCl和 10 -8mol/LPMA诱导的LH分泌 ,而 10 -7mol/LP短时间处理则起促进作用。当处理时间延长为 5 2h时 ,P对 6 0mmol/LKCl和 10 -8mol/LPMA诱导的LH分泌无明显作用 ,P也仅对 6 0mmol/LKCl刺激的LH分泌起抑制作用 ,但不影响 10 -8mol/LPMA诱导的LH分泌。当P和MP同时处理时 ,则MP可逆转P对高 [K+]e和PMA诱导的LH分泌的调节作用 ,表明MP影响GnRH诱导的LH分泌的机制可能与MP影响电压依赖性钙离子通道和PKC的活性有关。Clinical research has observed that Mifepristone(MP)could decrease gonadotropin secretion when it was administrated to the woman with normal menstrual cycle, whereas its undelying mechanisms are poorly understood. In this study, the action of MP on GnRH-, high extracellular K +([K +] e)-,Phorbol 12-myristate-13-acetate (PMA)-induced LH release in cultured rat anterior pituitary cells was investigated. The anterior pituitaries of the female mature Sprague Dawley rats were dissociated with 0.25% collagenase, 0.1% hyaluronadase and 10 μg DNase Ⅰ according to the method from Vale. Isolated pituitary cells were cultured with Ham F12 and Dulbecco modified Eagle Medium 1∶1 supplemented with charcoal treated fetal calf serum for three days and then exposed with MP or/and hormones. In short term treatment groups (4-hour treatment), cells were exposed in 3×10 -9 mol/L estaradiol(E 2) for 52 hours first and then 10 -7 mol/L MP or 10 -7 mol/L progesterone(P) or 10 -7 mol/L MP+ 10 -7 mol/L P was added in the medium at the last 4 hours of culture. In long term treatment groups, cells were exposed in 3×10 -9 mol/L E 2 semitaneously with either MP or P or MP+P for 52 hours and then treated with 10 -9 mol/L GnRH or 10 -8 mol/L PMA or 60 mmol/L K + for another 3 hours. The collected media were stored at -20℃ for luteinizing hormone(LH) radioimmunoassay. The results demonstrated that MP could inhibit GnRH-induced LH secretion in a dose- and time-dependent manner and also antagonized the regulatory effect of P on GnRH-induced LH secretion. Further studies showed that 4 hours treatment of MP could decrease KCl and PMA stimulated LH release and in contrary, P augmented KCl and PMA stimulated LH release. In the long term treatment groups, neither KCl nor PMA induced LH secretion was influenced by P, but P could inhibit the KCl stimulated LH secretion. When MP was treated concomitant with P, both stimulatory and inhibitory effects of P on the high [K +] e and PMA induced LH s

关 键 词：大鼠 垂体细胞 分泌 米非司酮 孕酮 促黄体激素 电压依赖性钙离子通道 钾离子 蛋白激素C 

分 类 号：Q575[生物学—生物化学]