Espey L L, Tanaka N, Winn V, Okamura H
Department of Biology, Trinity University, San Antonio, Texas 78284.
J Reprod Fertil. 1989 Nov;87(2):503-8. doi: 10.1530/jrf.0.0870503.
The ovulatory process was initiated in 25-day-old rats by injecting them with hCG (10 i.u., s.c.) 2 days after the animals had been primed with PMSG (10 i.u., s.c.). At 2-h intervals after hCG, the ovaries were extracted and assayed for glandular kallikrein activity by using a chromogenic substrate (H-D-Val-Leu-Arg-p-nitroanilide) which exhibits optical density (at 405 nm) upon hydrolysis. In 0-h control ovaries the activity was 12.5 x 10(-3) kallikrein units (KU)/mg protein and it increased to a peak of 56.6 x 10(-3) KU/mg at 12 h after hCG, when the follicles first began to rupture. The kallikrein activity was distinguishable from ovarian plasminogen activator activity on the basis of pH optima and response to trypsin inhibitor (SBTI). The activity was inhibited by a s.c. dose of indomethacin of 0.3 mg/rat, or higher, and this dosage inhibited ovulation. The results suggest that kallikrein activity contributes to the degradation of Graafian follicles during ovulation in mammals.
在25日龄大鼠中，在给予孕马血清促性腺激素（PMSG，10国际单位，皮下注射）进行预处理2天后，通过皮下注射人绒毛膜促性腺激素（hCG，10国际单位）启动排卵过程。在注射hCG后，每隔2小时取出卵巢，使用一种发色底物（H-D-缬氨酸-亮氨酸-精氨酸-对硝基苯胺）检测腺体激肽释放酶活性，该底物在水解时会表现出光密度（在405nm处）。在0小时的对照卵巢中，活性为12.5×10⁻³激肽释放酶单位（KU）/mg蛋白质，在hCG注射后12小时，当卵泡开始首次破裂时，活性增加到峰值56.6×10⁻³KU/mg。基于最适pH值和对胰蛋白酶抑制剂（SBTI）的反应，激肽释放酶活性与卵巢纤溶酶原激活剂活性是有区别的。皮下注射0.3mg/大鼠或更高剂量的吲哚美辛可抑制该活性，并且这种剂量会抑制排卵。结果表明，激肽释放酶活性在哺乳动物排卵过程中有助于格拉夫卵泡的降解。
