Kumar Srivastava R, Van Der Kraak G
Department of Zoology, University of Guelph, Ontario, Canada.
Gen Comp Endocrinol. 1995 Dec;100(3):397-403. doi: 10.1006/gcen.1995.1170.
The present study examines the interactive effects of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF alpha) with insulin, insulin-like growth factors I and II (IGF-I and IGF-II), and human chorionic gonadotropin (hCG) on DNA synthesis by goldfish ovarian follicles in vitro. DNA synthesis was assessed from the incorporation of [3H]thymidine. When tested individually, EGF, TGF alpha, insulin, IGFs, and hCG enhanced DNA synthesis by vitellogenic ovarian follicles. The interactive effects of EGF and TGF alpha on DNA synthesis by vitellogenic follicles were not additive, suggesting that these growth factors work through the same receptors. The most profound mitogenic effects of EGF and TGF alpha were seen when they were combined with insulin, IGF-I, or IGF-II. Unlike IGF-1, which had an additive effect when tested with hCG, EGF and hCG effects on DNA synthesis were not additive. Treatment with an antibody to EGF but neither gamma-globulin nor IGF-I antibody blocked the stimulatory actions of hCG on DNA synthesis by vitellogenic follicles. This suggests that EGF mediates the actions of hCG on DNA synthesis. In summary, these data support the concept that several growth factors and gonadotropins participate in the regulation of DNA synthesis in goldfish vitellogenic follicles.
本研究检测了表皮生长因子（EGF）、转化生长因子-α（TGFα）与胰岛素、胰岛素样生长因子I和II（IGF-I和IGF-II）以及人绒毛膜促性腺激素（hCG）对金鱼卵母细胞体外DNA合成的交互作用。通过[3H]胸腺嘧啶核苷的掺入来评估DNA合成。单独检测时，EGF、TGFα、胰岛素、IGF和hCG均可增强卵黄生成期卵巢卵泡的DNA合成。EGF和TGFα对卵黄生成期卵泡DNA合成的交互作用并非相加性的，这表明这些生长因子通过相同的受体发挥作用。当EGF和TGFα与胰岛素、IGF-I或IGF-II联合使用时，可观察到最显著的促有丝分裂作用。与IGF-1不同，IGF-1与hCG联合检测时有相加作用，而EGF和hCG对DNA合成的作用并非相加性的。用抗EGF抗体处理，但γ球蛋白和IGF-I抗体均未阻断hCG对卵黄生成期卵泡DNA合成的刺激作用。这表明EGF介导了hCG对DNA合成的作用。总之，这些数据支持了几种生长因子和促性腺激素参与金鱼卵黄生成期卵泡DNA合成调节的概念。
