Uilenbroek J T
Department of Endocrinology, Growth and Reproduction, Faculty of Medicine, Erasmus University, Rotterdam, The Netherlands.
J Endocrinol. 1991 Jun;129(3):423-9. doi: 10.1677/joe.0.1290423.
Administration of antiprogestagens (2 mg/day) to female rats for 21 days induces high serum prolactin levels. These levels stimulate luteal progesterone production and an increase in ovarian weight. Compared with RU486 (mifepristone) the increase in prolactin is less after treatment with ZK299 (onapristone), an antiprogestagen with lower antiglucocorticoid activity. To study whether cyclic ovulations occur in rats treated with antiprogestagens, 5-day cyclic rats were given daily injections of RU486 or ZK299 (2 mg) from metoestrus (day 1) to pro-oestrus. This treatment advanced the forthcoming ovulation by 1 day; however, the ovulation rate was low. Injection of 10 IU human chorionic gonadotrophin on the afternoon of pro-oestrus (day 3) increased the ovulation rate, but not to the level found in oil-treated rats. Serum LH concentrations measured from metoestrus to oestrus at 10.00 and 17.00 h were higher in antiprogestagen- than in oil-treated rats from day 2 (17.00 h) onwards. A low preovulatory LH surge was found in antiprogestagen-treated rats on the afternoon of pro-oestrus (day 3). Ovarian histology at the day of oestrus (day 4) confirmed the presence of a low LH surge as, besides ruptured follicles, unruptured follicles with dispersion of cumulus cells were present. The pro-oestrus surge of prolactin was also advanced by 24 h. The magnitude, however, was not different from that in oil-treated rats at day 4.(ABSTRACT TRUNCATED AT 250 WORDS)
给雌性大鼠连续21天每天注射抗孕激素（2毫克/天）会导致血清催乳素水平升高。这些水平会刺激黄体孕酮的产生以及卵巢重量增加。与RU486（米非司酮）相比，用ZK299（奥那司酮，一种具有较低抗糖皮质激素活性的抗孕激素）治疗后催乳素的增加较少。为了研究用抗孕激素治疗的大鼠是否会出现周期性排卵，从间情期（第1天）到发情前期，给处于5天周期的大鼠每天注射RU486或ZK299（2毫克）。这种治疗使即将到来的排卵提前了1天；然而，排卵率较低。在发情前期（第3天）下午注射10国际单位人绒毛膜促性腺激素可提高排卵率，但未达到用油处理的大鼠的排卵率水平。从间情期到发情期，在10.00和17.00 h测量的血清促黄体生成素（LH）浓度，从第2天（17.00 h）起，抗孕激素处理的大鼠比用油处理的大鼠更高。在发情前期（第3天）下午，抗孕激素处理的大鼠出现了低水平的排卵前LH高峰。发情期（第4天）的卵巢组织学证实了存在低水平的LH高峰，因为除了破裂的卵泡外，还存在卵丘细胞分散的未破裂卵泡。发情前期的催乳素高峰也提前了24小时。然而，其幅度与第4天用油处理的大鼠没有差异。（摘要截短至250字）
