Muramatsu T, Pinontoan R, Okumura J
Laboratory of Animal Nutrition, School of Agricultural Sciences, Nagoya University, Japan.
Comp Biochem Physiol C Pharmacol Toxicol Endocrinol. 1995 Jun;111(2):281-6. doi: 10.1016/0742-8413(95)00049-t.
Whole-body protein synthesis in chicken embryos was measured to examine the biopotency of fetal bovine serum, bovine insulin, recombinant human insulin, and recombinant human insulin-like growth factors (IGF) I and II. In all experiments chicken embryos at 7 days of incubation age were used and cultured in a synthetic serum-free medium in the presence or absence of the testing substances with a rotatory whole-embryo culture apparatus for up to 30 min. Whole-body protein synthesis was measured from the time course of specific radioactivities of free and protein-bound L-[4-3H]phenylalanine. In addition, the effect of bovine insulin on phenylalanine extraction rate from the culture medium was investigated. Supplementing the medium with fetal bovine serum and human IGF-I significantly enhanced whole-body protein synthesis. In contrast, human IGF-II, bovine insulin, or human insulin did not affect whole-body protein synthesis, although bovine insulin increased phenylalanine extraction rate from the culture medium in a proportional fashion as the dose increased. Therefore, from these results it was concluded that IGF-I, but not IGF-II, might be one of the anabolic factors in fetal bovine serum for stimulating whole-body protein synthesis, and that insulin may play a role in stimulating amino acid transport, but it may not be directly involved in protein synthesis of chicken embryos.
通过测量鸡胚的全身蛋白质合成来检测胎牛血清、牛胰岛素、重组人胰岛素以及重组人胰岛素样生长因子（IGF）-I和IGF-II的生物活性。在所有实验中，均使用孵化7天的鸡胚，并在有无受试物质的情况下，使用旋转式全胚培养装置在无血清合成培养基中培养长达30分钟。根据游离型和蛋白质结合型L-[4-³H]苯丙氨酸的比放射性随时间的变化过程来测量全身蛋白质合成。此外，还研究了牛胰岛素对培养基中苯丙氨酸提取率的影响。向培养基中添加胎牛血清和人IGF-I可显著增强全身蛋白质合成。相比之下，人IGF-II、牛胰岛素或人胰岛素对全身蛋白质合成没有影响，尽管牛胰岛素可使培养基中苯丙氨酸提取率随剂量增加而成比例增加。因此，根据这些结果可以得出结论，IGF-I而非IGF-II可能是胎牛血清中刺激全身蛋白质合成的合成代谢因子之一，并且胰岛素可能在刺激氨基酸转运中发挥作用，但它可能不直接参与鸡胚的蛋白质合成。
