Kramer P, Meijs-Roelofs H M
J Endocrinol. 1982 Jan;92(1):31-5. doi: 10.1677/joe.0.0920031.
The effect was studied of five daily injections of 50 microgram of either 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha-androstanediol) or its 3 beta-epimer (3 beta-androstanediol), starting on day 22 of life, on sexual maturation in female rats. No difference was found in the age and body weight at first oestrus between oil-treated rats and rats treated with either 3 alpha- or 3 beta-androstanediol. The only difference observed between these groups consisted of the occurrence of a "pinhole" vaginal opening a few days before oestrus in 50% of the steroid-treated rats; in oil-treated rats immediate full vaginal opening and first oestrus coincided in ten out of 12 rats. Different effects were obtained when the higher dose of 100 microgram daily was used; effects were dissimilar in rats treated with 3 alpha- and 3 beta-androstanediol. If administration of the higher dose of 3 beta-androstanediol was started on day 22 and continued until the day of full vaginal opening and first oestrus, a significant delay of this first oestrus, preceded by a few days of a "pinhole" type of vaginal opening was observed. After administration of the higher dose of 3 alpha-androstanediol a "pinhole" type of vaginal opening, accompanied by dioestrous-like vaginal smears, was also found, but oestrus did not occur during the period when injections were given. After the injections were stopped on day 45, first oestrus developed within 6 days in all rats. The previous findings of others that administration of 3 beta-androstanediol to the immature female rat may induce precocious puberty (i.e. precocious vaginal opening and first ovulation) were not confirmed in the present study. Out results indicate that high doses of free 3 alpha-androstanediol, and to a lesser degree 3 beta-androstanediol, may even delay first ovulation in the rat. A possible interference of 3 alpha-androstanediol with the triggering of the first ovulatory gonadotrophin peaks is discussed.
研究了从出生后第22天开始，每日5次注射50微克的5α-雄甾烷-3α,17β-二醇（3α-雄甾二醇）或其3β-差向异构体（3β-雄甾二醇）对雌性大鼠性成熟的影响。用油处理的大鼠与用3α-或3β-雄甾二醇处理的大鼠在首次发情时的年龄和体重上未发现差异。这些组之间观察到的唯一差异在于，50%接受类固醇处理的大鼠在发情前几天出现“针孔状”阴道口；在接受油处理的大鼠中，12只大鼠中有10只阴道口立即完全张开并同时出现首次发情。当使用每日100微克的更高剂量时，得到了不同的效果；用3α-和3β-雄甾二醇处理的大鼠效果不同。如果从第22天开始给予更高剂量的3β-雄甾二醇并持续到阴道口完全张开和首次发情之日，则观察到首次发情明显延迟，之前有几天是“针孔状”阴道口。给予更高剂量的3α-雄甾二醇后，也发现了“针孔状”阴道口，并伴有动情间期样的阴道涂片，但在注射期间未出现发情。在第45天停止注射后，所有大鼠在6天内出现首次发情。其他人先前关于给未成熟雌性大鼠注射3β-雄甾二醇可能诱导性早熟（即早熟的阴道口张开和首次排卵）的发现，在本研究中未得到证实。我们的结果表明，高剂量的游离3α-雄甾二醇，以及程度较轻的3β-雄甾二醇，甚至可能延迟大鼠的首次排卵。讨论了3α-雄甾二醇对首次排卵促性腺激素峰值触发的可能干扰。
