Sawada T, Kosaka T, Ichikawa S
Department of Animal Reproduction, College of Agriculture, University of Osaka Prefecture, Japan.
Acta Endocrinol (Copenh). 1987 Nov;116(3):390-4. doi: 10.1530/acta.0.1160390.
Differences in the secretion of pregnane compounds by ovaries with cystic follicles of rats exposed to constant light (light-induced oestrous rats) and by ovaries with normal follicles of early pro-oestrous rats were studied. Some rats were injected iv with 2 micrograms of LH to stimulate the secretion of steroids 30 min before their blood was sampled. The injection greatly increased the secretion of progesterone by both kinds of ovaries. The secretion of 5 alpha-pregnane-3,20-dione and 3 alpha-hydroxy-5 alpha-pregnan-20-one also increased in normal rats, but not in the polycystic ovaries of light-induced oestrous rats, which suggested that the 5 alpha-reductase activity was low. The pre-ovulatory LH surge is absent in light-induced oestrous rats, so a classic approach was taken to circumvent the probable deficit in the cyclic release of LH; we gave multiple injections of 10 micrograms of LH. Five such injections were given at intervals of 4 days, and ovarian venous blood was collected 4 days after the last injection. Cystic follicles in the ovaries of rats disappeared when the injections of LH were given every 4 days. The production of 5 alpha-pregnane-3,20-dione and 3 alpha-hydroxy-5 alpha-pregnan-20-one from the ovaries of such rats was significantly higher (P less than 0.01) than in controls given multiple injections of saline. These results suggest that the low 5 alpha-reductase activity in polycystic ovaries of light-induced oestrous rats may be due to the absence of an LH surge from the pituitary gland.
研究了持续光照下大鼠（光诱导发情大鼠）具有囊性卵泡的卵巢与早期动情前期大鼠具有正常卵泡的卵巢中孕烷化合物分泌的差异。一些大鼠在采血前30分钟静脉注射2微克促黄体生成素（LH）以刺激类固醇分泌。该注射显著增加了两种卵巢中孕酮的分泌。正常大鼠中5α-孕烷-3,20-二酮和3α-羟基-5α-孕烷-20-酮的分泌也增加，但光诱导发情大鼠的多囊卵巢中未增加，这表明5α-还原酶活性较低。光诱导发情大鼠中不存在排卵前LH峰，因此采用经典方法来规避LH周期性释放可能存在的不足；我们多次注射10微克LH。每隔4天进行5次这样的注射，并在最后一次注射后4天收集卵巢静脉血。当每4天注射LH时，大鼠卵巢中的囊性卵泡消失。这些大鼠卵巢中5α-孕烷-3,20-二酮和3α-羟基-5α-孕烷-20-酮的产生显著高于多次注射生理盐水的对照组（P<0.01）。这些结果表明，光诱导发情大鼠多囊卵巢中5α-还原酶活性较低可能是由于垂体缺乏LH峰所致。
