Matousek M, Mikuni M, Mitsube K, Yoshida M, Brännström M
Department of Obstetrics and Gynaecology, Göteborg University, Sweden.
J Reprod Fertil. 1999 Nov;117(2):379-85. doi: 10.1530/jrf.0.1170379.
Protein tyrosine kinase activity, leading to tyrosine phosphorylation of the intracellular domains of receptors or non-receptor proteins, is an important feature of downstream signalling after receptor binding of a variety factors, such as growth factors and cytokines. Since several members of these classes of paracrine-autocrine mediator may be involved in the intraovarian events of ovulation, the present study was designed to evaluate the effect of protein tyrosine kinase inhibition on the in vitro perfused rat ovary. Immature rats were primed with 20 iu pregnant mares' serum gonadotrophin 48 h before surgical isolation of the right ovary with connecting vasculature. The ovary was placed in a perfusion system for either 10 h, to examine ovarian concentrations of the established ovulatory mediators plasminogen activator, prostaglandins E2 and F2 alpha, or for 20 h, enabling a complete ovulatory process to occur in vitro. Ovulation was induced by ovine LH (0.2 microgram ml-1) in the presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (0.2 mmol l-1) and the effects of two different protein tyrosine kinase inhibitors, genistein and tyrphostin A25, were studied. Unstimulated control ovaries did not ovulate and showed low secretion of progesterone and oestradiol. Addition of LH + 3-isobutyl-1-methylxanthine resulted in a marked stimulation of steroid release, and ovulations occurred in all ovaries (9.0 +/- 0.9; mean +/- SEM). The protein tyrosine kinase inhibitors, genistein and tyrphostin A25, significantly inhibited ovulation at the higher concentrations tested (3.0 +/- 0.3 at 100 mumol genistein l-1; 5.8 +/- 1.0 at 500 mumol tyrphostin A25 l-1) but no effect was seen at lower concentrations. The presence of genistein and tyrphostin A25 at any concentration used did not significantly decrease the LH + 3-isobutyl-1-methylxanthine-induced progesterone or oestradiol concentrations. The intraovarian concentrations of plasminogen activator activity, and prostaglandin E2 and F2 alpha were not altered by the presence genistein (100 mumol l-1). In conclusion, the results of the present study indicate that protein tyrosine kinase signalling pathways are integral parts of the mammalian ovulatory process but do not involve actions on the synthesis of steroids, plasminogen activator or prostaglandins.
蛋白质酪氨酸激酶活性可导致受体或非受体蛋白的细胞内结构域发生酪氨酸磷酸化，这是多种因子（如生长因子和细胞因子）与受体结合后下游信号传导的一个重要特征。由于这些旁分泌 - 自分泌介质类别的几个成员可能参与卵巢内排卵事件，本研究旨在评估蛋白质酪氨酸激酶抑制对体外灌注大鼠卵巢的影响。未成熟大鼠在手术分离右侧卵巢及其相连血管前48小时用20国际单位孕马血清促性腺激素进行预处理。将卵巢置于灌注系统中10小时，以检测已确定的排卵介质纤溶酶原激活剂、前列腺素E2和F2α的卵巢浓度，或置于灌注系统中20小时，以使体外发生完整的排卵过程。在磷酸二酯酶抑制剂3 - 异丁基 - 1 - 甲基黄嘌呤（0.2 mmol/L）存在的情况下，用绵羊促黄体生成素（0.2 μg/ml）诱导排卵，并研究两种不同的蛋白质酪氨酸激酶抑制剂染料木黄酮和 tyrphostin A25的作用。未受刺激的对照卵巢不排卵，孕酮和雌二醇分泌量低。添加促黄体生成素 + 3 - 异丁基 - 1 - 甲基黄嘌呤可显著刺激类固醇释放，所有卵巢均发生排卵（9.0 ± 0.9；平均值 ± 标准误）。蛋白质酪氨酸激酶抑制剂染料木黄酮和tyrphostin A25在测试的较高浓度下（100 μmol/L染料木黄酮时为3.0 ± 0.3；500 μmol/L tyrphostin A25时为5.8 ± 1.0）显著抑制排卵，但在较低浓度下未见效果。所用任何浓度的染料木黄酮和tyrphostin A25均未显著降低促黄体生成素 + 3 - 异丁基 - 1 - 甲基黄嘌呤诱导的孕酮或雌二醇浓度。染料木黄酮（100 μmol/L）的存在未改变卵巢内纤溶酶原激活剂活性以及前列腺素E2和F2α的浓度。总之，本研究结果表明蛋白质酪氨酸激酶信号通路是哺乳动物排卵过程的组成部分，但不涉及对类固醇、纤溶酶原激活剂或前列腺素合成的作用。
