Kaneko H, Taya K, Sasamoto S
Laboratory of Veterinary Physiology, Tokyo University of Agriculture and Technology, Japan.
Life Sci. 1987 Oct 12;41(15):1823-30. doi: 10.1016/0024-3205(87)90701-6.
Sequential changes in the function of antral follicles during the period of follicular atresia were investigated after hypophysectomy (Hypox) at 1100 hr on proestrus. Within 6 hours after Hypox, concentrations of progesterone (P), testosterone (T) and estradiol-17 beta (E) decreased abruptly in ovarian venous plasma (OVP) and follicles showed a reduced ability to ovulate. Six hours after Hypox, ovulation was still induced by human chorionic gonadotropin (hCG) in all animals but with significantly fewer number of oocytes compared to the group given hCG at 1100 hr on the day of proestrus. Nine hours after Hypox, several granulosa cells of all large follicles (greater than 400 microns in diameter) exhibited morphological signs of atresia. Twelve hours after Hypox, all large and medium sized (200-400 microns in diameter) follicles showed advanced stages of atresia and almost all follicles failed to ovulate in response to hCG. Inhibin activity in OVP declined more slowly compared to the profiles of steroid hormones and 53% of the initial inhibin activity was still maintained at 18 hours after the operation. Inhibin activity further decreased to 7% of the initial level at 24 hours and was undetectable by 48 hours after Hypox. These results suggest that fully developed Graafian follicles gradually lose their ability to secrete inhibin in contrast to the rapid decrease in secretion of steroid hormone during the process of atresia.
在动情前期1100时进行垂体切除术后，研究了闭锁卵泡期窦卵泡功能的连续变化。垂体切除术后6小时内，卵巢静脉血浆（OVP）中孕酮（P）、睾酮（T）和雌二醇-17β（E）的浓度急剧下降，卵泡排卵能力降低。垂体切除术后6小时，所有动物均仍可通过人绒毛膜促性腺激素（hCG）诱导排卵，但与动情前期当天1100时给予hCG的组相比，卵母细胞数量明显减少。垂体切除术后9小时，所有大卵泡（直径大于400微米）的一些颗粒细胞出现闭锁的形态学迹象。垂体切除术后12小时，所有大、中卵泡（直径200 - 400微米）均显示出晚期闭锁，几乎所有卵泡对hCG均无排卵反应。与甾体激素的变化情况相比，OVP中抑制素活性下降较慢，术后18小时仍维持初始抑制素活性的53%。垂体切除术后24小时，抑制素活性进一步降至初始水平的7%，术后48小时检测不到。这些结果表明，与闭锁过程中甾体激素分泌迅速减少相反，完全发育的格拉夫卵泡逐渐丧失分泌抑制素的能力。
