Campbell B K, Engelhardt H, McNeilly A S, Harkness L M, Fukuoka M, Baird D T
Department of Obstetrics and Gynaecology, University of Edinburgh, UK.
J Reprod Fertil. 1999 Nov;117(2):259-69. doi: 10.1530/jrf.0.1170259.
The objective of this study was to assess the effect of ovine follicular fluid (FF) treatment (with or without FSH replacement) during the late follicular phase on plasma concentrations of gonadotrophins and the development of the ovulatory follicle. Ovarian steroid secretion and expression of mRNA encoding inhibin alpha and beta A, beta B subunits, P450 aromatase and P450 17 alpha-hydroxylase were used as endpoints. After induction of luteolysis by injection of 100 micrograms cloprostenol on days 10-12, Scottish Blackface ewes were allocated to one of three groups: (1) control (n = 7): no further treatment; (2) FF (n = 9): subcutaneous injections of 3 ml steroid-free ovine follicular fluid at 9 h intervals, 18 and 27 h after cloprostenol injection; (3) FF + FSH (n = 8): injections of follicular fluid as above plus subcutaneous injections of 0.36 iu ovine FSH at 6 h intervals, 18, 24, and 30 h after cloprostenol injection. Jugular venous blood samples were obtained via indwelling cannulae at 6 h intervals from 0 to 36 h after cloprostenol injection, and at 10 min intervals from 12 to 18 h (control phase) and from 30 to 36 h after cloprostenol injection (treatment phase). At laparotomy, 36 h after cloprostenol injection, ovarian venous blood was collected and ovaries were removed and processed for in situ hybridization. Plasma concentrations of FSH, luteinizing hormone (LH) and oestradiol were determined by radioimmunoassay. Follicular fluid treatment resulted in a decrease (P < 0.001) in FSH concentrations associated with an acute decrease in ovarian steroid secretion (P < 0.01) and a specific depression in P450 aromatase, (P < 0.001), inhibin-activin beta B subunit (P < 0.05) and thecal LH receptor (P < 0.001) expression. Follicular fluid treatment had no effect on inhibin-activin alpha and beta A, subunit or P450 17 alpha-hydroxylase expression. FSH co-treatment with follicular fluid restored circulating FSH concentrations to normal values and reversed some of the effects of follicular fluid (androstenedione, testosterone and progesterone secretion, and inhibin beta B and thecal LH receptor expression) but not oestradiol secretion or P450 aromatase expression. It was concluded that the actions of follicular fluid are mediated via both central effects on pituitary FSH secretion and by direct ovarian effects on granulosa cell aromatase activity. The results indicate that follicular fluid contains a factor that inhibits aromatase activity of granulosa cells directly and may play a role in the selection of the dominant follicle.
本研究的目的是评估卵泡晚期绵羊卵泡液（FF）处理（有无促卵泡素（FSH）替代）对促性腺激素血浆浓度及排卵卵泡发育的影响。将卵巢类固醇分泌以及编码抑制素α和βA、βB亚基、P450芳香化酶和P450 17α-羟化酶的mRNA表达作为研究终点。在第10 - 12天注射100微克氯前列醇诱导黄体溶解后，将苏格兰黑脸母羊分为三组之一：（1）对照组（n = 7）：不进行进一步处理；（2）FF组（n = 9）：在注射氯前列醇后18和27小时，每隔9小时皮下注射3毫升无类固醇的绵羊卵泡液；（3）FF + FSH组（n = 8）：按上述方法注射卵泡液，外加在注射氯前列醇后18、24和30小时每隔6小时皮下注射0.36国际单位绵羊FSH。在注射氯前列醇后0至36小时每隔6小时，以及在12至18小时（对照期）和注射氯前列醇后30至36小时（处理期）每隔10分钟，通过留置套管采集颈静脉血样。在注射氯前列醇后36小时进行剖腹手术时，采集卵巢静脉血，切除卵巢并进行原位杂交处理。通过放射免疫测定法测定FSH、黄体生成素（LH）和雌二醇的血浆浓度。卵泡液处理导致FSH浓度降低（P < 0.001），同时卵巢类固醇分泌急剧减少（P < 0.01），P450芳香化酶、抑制素 - 激活素βB亚基（P < 0.05）和卵泡膜LH受体（P < 0.001）表达出现特异性降低。卵泡液处理对抑制素 - 激活素α和βA亚基或P450 17α-羟化酶表达无影响。FSH与卵泡液联合处理可使循环FSH浓度恢复到正常水平，并逆转卵泡液的一些作用（雄烯二酮、睾酮和孕酮分泌，以及抑制素βB和卵泡膜LH受体表达），但不能逆转雌二醇分泌或P450芳香化酶表达。得出的结论是，卵泡液的作用是通过对垂体FSH分泌的中枢作用以及对颗粒细胞芳香化酶活性的直接卵巢作用介导的。结果表明，卵泡液含有一种直接抑制颗粒细胞芳香化酶活性的因子，可能在优势卵泡的选择中起作用。
