Waksman M, Shamay A, Gertler A
Department of Biochemistry and Human Nutrition, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot, Israel.
Domest Anim Endocrinol. 1991 Apr;8(2):271-80. doi: 10.1016/0739-7240(91)90063-p.
Bovine mammary undifferentiated epithelial cells from young female calves, cultured in three-dimensional collagen gels in serum-free medium exhibited ultrastructural organization that resembled the in vivo situation. Extracts of bovine pituitary, kidney, uterus and mammary gland, stimulated cell proliferation in a dose-dependent manner. This mitogenic activity strongly synergised with the existant growth factors (GFs) in FCS and with IGF-I, while the addition of EGF had only minor effect. No synergistic manifestation was found with cholera toxin but pertussis toxin inhibited the growth-promoting activity of all four extracts. Other experiments indicated that this mitogenic activity does not result from prolactin, growth hormone or fibroblast growth factor. The present and former results, in which synergism between IGF-I and cholera toxin was demonstrated, suggest therefore, that the mitogenesis of normal mammary epithelial cells regulated by several tissue derived growth factors, consists of at least two pathways which are distinct from those activated by EGF and IGF-I. One of these pathways indicates involvement of pertussis toxin-sensitive GTP-binding proteins, and the other, activation of cholera toxin-sensitive adenylate cyclase.
来自幼年母牛的乳腺未分化上皮细胞，在无血清培养基中的三维胶原凝胶中培养时，呈现出类似于体内情况的超微结构组织。牛垂体、肾脏、子宫和乳腺的提取物以剂量依赖的方式刺激细胞增殖。这种促有丝分裂活性与胎牛血清中的现有生长因子（GFs）以及胰岛素样生长因子-I（IGF-I）强烈协同，而添加表皮生长因子（EGF）的影响较小。未发现与霍乱毒素有协同表现，但百日咳毒素抑制了所有四种提取物的促生长活性。其他实验表明，这种促有丝分裂活性不是由催乳素、生长激素或成纤维细胞生长因子引起的。因此，目前以及之前证明IGF-I与霍乱毒素之间存在协同作用的结果表明，正常乳腺上皮细胞的有丝分裂由几种组织衍生的生长因子调节，至少由两条不同于EGF和IGF-I激活的途径组成。其中一条途径表明涉及百日咳毒素敏感的GTP结合蛋白，另一条途径是霍乱毒素敏感的腺苷酸环化酶的激活。
