孕三烯酮紧急避孕机理的初步探讨

Mechanism of emergency contraception with gestrinone:a preliminary investigation.

目的研究小剂量（5mg）孕三烯酮作紧急避孕时其对卵巢功能和子宫内膜的影响。方法15名健康妇女随机分为A、B两组。A组（n=8）在排卵前（-2天）服药,B组（n=7）在排卵后（＋2天）服药。用阴道B-超监测卵泡生长发育。A、B两组的对照周期与服药周期均在排卵后第5或7天（＋5,＋7）刮取子宫内膜,应用免疫组化法检测ER、PR、整合素（α1β1、α4β1、β3）的分布与含量。同时留取排卵前2～4天至排卵后5～7天静脉血,用放射免疫法测定血清雌二醇（E2）、孕酮（P）水平。结果围排卵期单次口服5mg孕三烯酮对卵泡发育、排卵及血清中雌、孕激素水平均无明显影响,但可下调子宫内膜ER、PR蛋白含量,并使子宫内膜整合素α4β1蛋白含量增加。结论孕三烯酮紧急避孕的机理可能是通过影响子宫内膜雌、孕激素受体含量及“植入窗口”期参与粘附过程的整合素的表达,而干扰孕卵植入。

Objective： To study the effect of a single oral dose of gestrinone given for EC on ovarian function and endometrial development. Methods： Healthy fertile women were randomly assigned to group A （n = 8） or group B （n = 7）. 5mg gestrinone was administered to each woman before （ Group A） or after （ Group B） ovulation. The day of ovulation was determined by transvaginal ultrasound and by urinary LH measured with enzyme immunoassay. An endometrial biopsy was performed during the implantation period. Endometrial maturation and expression of markers of endometrial receptivity were analyzed. The tested markers were integrins α1β1, α4β1, and β3.Estradiol and progesterone levels in serum were determined by radioimmunoassay and their receptors （ER and PR） in endometrium were assessed by immunohistochemistry. Results： Gestrlnone administered during the periovulatory period did not affect follicular development, ovulation, menstrual cycle length, serum estradiol and progesterone, levels, but decreased the expression of PR in the endometriurn. Integrin α4β1 tended to increase after treatment with gestrinone without reaching statistically significance. Conclusion： The mode of action of gestrinone used for EC is probably inhibition of implantation by acting on the endometrium rather than inhibition of ovulation.