Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessalia, Larissa, Greece; Department of Obstetrics and Gynaecology, Medical School, University of Thrace, Alexandroupolis, Greece.
Clin Endocrinol (Oxf). 2014 Mar;80(3):439-43. doi: 10.1111/cen.12306. Epub 2013 Aug 28.
Oestradiol sensitizes the pituitary to GnRH, while gonadotrophin surge attenuating factor (GnSAF) may oppose this action. Using the LH response to GnRH during treatment with FSH as an in vivo bioassay for GnSAF, we tested the hypothesis that the augmented LH response to GnRH in the late follicular phase is related to reduced production of GnSAF from the ovulatory follicle.
Prospective intervention study.
Ten healthy, normally cycling women.
The LH response to 10 μg GnRH i.v. (ΔLH) was investigated on days 2 and 3 and on days v (follicle size 16-17 mm) and v + 1 of cycle 1 (control) and cycle 2. On days 2 and v, a single s.c. injection of either normal saline (cycle 1) or 450 IU recombinant FSH (cycle 2) was given after the end of the GnRH experiment.
FSH injection increased both serum oestradiol and inhibin B. In cycle 1, ΔLH remained unchanged from days 2 to 3 but increased significantly from days v to v + 1. In contrast, in cycle 2, ΔLH decreased significantly from days 2 to 3 (P < 0·05) and showed a nonsignificant increase from day v to day v + 1. The percentage difference in ΔLH between cycle 1 and cycle 2 was similar on days 3 (-66·9 ± 17·5%) and v + 1 (-65·2 ± 3·6%).
These results suggest that during the follicular phase of the menstrual cycle, GnSAF is produced by small antral follicles, while the contribution of the ovulatory follicle is minimal.
雌激素使垂体对 GnRH 敏感，而促性腺激素释放激素抑制因子（GnSAF）可能会拮抗这种作用。我们利用 FSH 治疗期间 GnRH 引起的 LH 反应作为 GnSAF 的体内生物测定，检验这样一种假设，即在卵泡晚期 GnRH 引起的 LH 反应增强与排卵卵泡产生的 GnSAF 减少有关。
前瞻性干预研究。
10 名健康、正常排卵的妇女。
在第 1 周期和第 2 周期的第 2 天和第 3 天以及 v 天（卵泡大小 16-17mm）和 v+1 天，静脉内给予 10μg GnRH 后，检测 LH 对 10μg GnRH 的反应（ΔLH）。在第 2 天和 v 天，在 GnRH 实验结束后，皮下注射生理盐水（第 1 周期）或 450IU 重组 FSH（第 2 周期）。
FSH 注射增加了血清雌二醇和抑制素 B。在第 1 周期，ΔLH 从第 2 天到第 3 天保持不变，但从 v 天到 v+1 天显著增加。相反，在第 2 周期，ΔLH 从第 2 天到第 3 天显著降低（P<0.05），从 v 天到 v+1 天呈非显著增加。第 1 周期和第 2 周期的 ΔLH 百分比差异在第 3 天相似（-66.9±17.5%）和 v+1 天相似（-65.2±3.6%）。
这些结果表明，在月经周期的卵泡期，GnSAF 由小窦卵泡产生，而排卵卵泡的贡献最小。
