Tsafriri A, Abisogun A O, Reich R
Department of Hormone Research, Weizmann Institute of Science, Rehovot, Israel.
J Steroid Biochem. 1987;27(1-3):359-63. doi: 10.1016/0022-4731(87)90328-1.
The preovulatory surge of gonadotropins stimulates follicular steroidogenesis and changes from estrogen as the major product to progesterone. We shall overview the studies dealing with the role of ovarian steroidogenesis in follicular rupture at ovulation. Several inhibitors of steroidogenesis blocked follicular rupture in vivo. Likewise, RU 38486 partially blocked ovulation triggered by hCG. Collectively, these data support the knowledge that follicular steroidogenesis is required for ovulation. Recent studies confirmed the essential role of plasminogen activator (PA) in follicular rupture. The LH stimulation of PA activity was partially blocked by several inhibitors of steroidogenesis and it could be restored by the addition of progesterone, testosterone and estradiol-17 beta, but not the non-aromatizable 5 alpha-dihydrotestosterone. Gonadotropic stimulation enhanced only the synthesis of tissue type PA (t-PA) and not that of urokinase. Likewise, inhibition of steroidogenesis, reduced only the synthesis of t-PA and was reversed by addition of estradiol-17 beta. It seems, therefore, that follicular steroids, most probably estrogen, are involved in the preovulatory rise in follicular t-PA activity.
促性腺激素的排卵前激增刺激卵泡类固醇生成，并使主要产物从雌激素转变为孕酮。我们将概述有关卵巢类固醇生成在排卵时卵泡破裂中作用的研究。几种类固醇生成抑制剂在体内阻断了卵泡破裂。同样，RU 38486部分阻断了hCG触发的排卵。总体而言，这些数据支持了排卵需要卵泡类固醇生成这一认识。最近的研究证实了纤溶酶原激活物（PA）在卵泡破裂中的重要作用。促黄体生成素（LH）对PA活性的刺激被几种类固醇生成抑制剂部分阻断，并且通过添加孕酮、睾酮和雌二醇-17β可以恢复，但不可芳香化的5α-二氢睾酮则不能。促性腺激素刺激仅增强了组织型PA（t-PA）的合成，而未增强尿激酶的合成。同样，类固醇生成的抑制仅降低了t-PA的合成，并通过添加雌二醇-17β得以逆转。因此，似乎卵泡类固醇，很可能是雌激素，参与了卵泡t-PA活性的排卵前升高。
