Elstein M, Morris S E, Groom G V, Jenner D A, Scarisbrick J J, Cameron E H
Fertil Steril. 1976 Aug;27(8):892-9. doi: 10.1016/s0015-0282(16)42008-x.
A study was undertaken to determine the effects of a low-dose oral contraceptive comprising 150 mug of D-norgestrel and 30 mug of 17alpha-ethynyl estradiol (Microgynon) on the plasma levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), 17BETA-ESTRADIOL, AND PROGESTERONE AND ON THE PHYSICAl properties of cervical mucus. Samples of blood and cervical mucus were obtained from three women during a treated cycle and the immediately-following "withdrawal" cycle. Specific radioimmunoassay methods were used to determine LH, FSH, 17beta-estradiol, and progesterone levels in treated and withdrawal cycles, and D-norgestrel and 17alpha-ethynyl estradiol in samples obtained during treated cycles. The concentration of synthetic steroids was also measured in blood samples obtained before and 1 hour after ingestion of the contraceptive to determine the maximal daily variation. The results indicated that the contraceptive action of this combined low-dose oral contraceptive is mediated through suppression of ovulation and by rendering the cervical mucus impenetrable to sperm. Plasma FSH levels appeared to be one of the most sensitive indices of suppression. Determination of D-norgestrel and 17alpha-ethynyl estradiol showed that 3 to 4 days were required to reach maximal plasma levels and that daily fluctuations were considerable. Withdrawal of the pill resulted in an immediate return to ovulatory cycles in all three subjects studied.
开展了一项研究，以确定一种低剂量口服避孕药（含150微克炔诺孕酮和30微克17α - 乙炔雌二醇（妈富隆））对促卵泡激素（FSH）、促黄体生成素（LH）、17β - 雌二醇和孕酮的血浆水平以及宫颈黏液物理性质的影响。在一个服药周期及紧接着的“停药”周期中，从三名女性身上采集血液和宫颈黏液样本。采用特定的放射免疫测定方法来测定服药周期和停药周期中的LH、FSH、17β - 雌二醇和孕酮水平，以及服药周期中采集样本里的炔诺孕酮和17α - 乙炔雌二醇。还在服用避孕药前及服药1小时后的血样中测量合成类固醇的浓度，以确定每日最大变化量。结果表明，这种低剂量复方口服避孕药的避孕作用是通过抑制排卵以及使宫颈黏液阻止精子穿透来介导的。血浆FSH水平似乎是抑制作用最敏感的指标之一。对炔诺孕酮和17α - 乙炔雌二醇的测定显示，达到血浆最高水平需要3至4天，且每日波动相当大。在所研究的三名受试者中，停药后均立即恢复排卵周期。
