Dorrington J H, Bendell J J, Lobb D K
Banting and Best Department of Medical Research, University of Toronto, Ontario, Canada.
Steroids. 1987 Oct-Dec;50(4-6):411-21. doi: 10.1016/0039-128x(87)90028-6.
This study describes the effects of insulin, insulin-like growth factor 1 (IGF1), and epidermal growth factor (EGF) on the aromatase activity of granulosa cells isolated from immature rat ovaries. None of the growth factors alone influenced the basal level of aromatase activity, but did modulate follicle-stimulating hormone (FSH)-induced aromatase activity. Insulin and IGF1 augmented the action of a sub-optimal concentration of FSH (5 ng/mL) on aromatase activity in a dose-dependent manner. In contrast, EGF (1-10 ng/mL) was effective in inhibiting aromatase activity maximally stimulated by FSH. Since insulin and IGF1 had opposing actions to those of EGF on FSH-induced aromatase activity, we examined the interactions between the growth factors. EGF inhibited the actions of both FSH and insulin on aromatase activity. Both IGF1 and EGF increased the [3H]thymidine incorporation into the DNA of bovine granulosa cells in vitro, IGF1 being a more potent mitogen. Whereas EGF inhibited the actions of IGF1 on aromatase activity, it did not inhibit the effects of IGF1 on the growth of granulosa cells. In summary, growth factors influence both the differentiation and growth of granulosa cells, and may be important regulators of follicular development.
本研究描述了胰岛素、胰岛素样生长因子1（IGF1）和表皮生长因子（EGF）对从未成熟大鼠卵巢分离出的颗粒细胞芳香化酶活性的影响。单独一种生长因子均不影响芳香化酶活性的基础水平，但确实能调节促卵泡激素（FSH）诱导的芳香化酶活性。胰岛素和IGF1以剂量依赖方式增强次优浓度FSH（5 ng/mL）对芳香化酶活性的作用。相反，EGF（1 - 10 ng/mL）能有效抑制FSH最大刺激的芳香化酶活性。由于胰岛素和IGF1对FSH诱导的芳香化酶活性的作用与EGF相反，我们研究了这些生长因子之间的相互作用。EGF抑制FSH和胰岛素对芳香化酶活性的作用。IGF1和EGF均能在体外增加[3H]胸腺嘧啶核苷掺入牛颗粒细胞DNA，IGF1是更强效的有丝分裂原。虽然EGF抑制IGF1对芳香化酶活性的作用，但不抑制IGF1对颗粒细胞生长的影响。总之，生长因子影响颗粒细胞的分化和生长，可能是卵泡发育的重要调节因子。
