Kanetake H, Yamamoto N
Invest Urol. 1981 Mar;18(5):326-30.
When synchronized primary rabbit kidney confluent monolayer cell cultures were incubated with a medium that contained uninephrectomized rabbit serum, the incorporation of tritiated thymidine into DNA was much greater than that with a medium that contained normal rabbit serum. The maximal growth stimulating activity of uninephrectomized serum on thymidine incorporation into sparsely cultured cells was increased approximately 5 fold above that of normal serum. We conclude that uninephrectomized sera contain a growth stimulating factor. Uninephrectomized rabbit sera showed no increased stimulation of DNA synthesis in primary rabbit skin cultured cells above that by normal rabbit serum, indicating that the growth stimulating factor in uninephrectomized serum shows renotropic specificity in tissue culture. A transformed rabbit kidney cell line RK-13 did not respond to the renotropic growth stimulating factor. However, primary and the transformed rabbit kidney cells absorbed the renotropic growth stimulating factor from uninephrectomized sera. Thus, the cell line RK-13 has receptors for adsorption of the renotropic growth factor but is unable to respond further to the growth stimulating process. The renotropic growth stimulating factor is heat unstable and undialyzable by dialysis tubings with pore size up to 12,000 molecular weight. Thus the renotropic growth factor seems to be a macromolecule, probably a protein.
当同步化的原代兔肾汇合单层细胞培养物与含有单侧肾切除兔血清的培养基一起孵育时，氚标记胸腺嘧啶核苷掺入DNA的量比与含有正常兔血清的培养基孵育时要多得多。单侧肾切除血清对稀疏培养细胞中胸腺嘧啶核苷掺入的最大生长刺激活性比正常血清增加了约5倍。我们得出结论，单侧肾切除血清中含有一种生长刺激因子。单侧肾切除兔血清对原代兔皮肤培养细胞中DNA合成的刺激作用并不比正常兔血清更强，这表明单侧肾切除血清中的生长刺激因子在组织培养中表现出促肾生长特异性。一种转化的兔肾细胞系RK - 13对促肾生长刺激因子没有反应。然而，原代和转化的兔肾细胞能从单侧肾切除血清中吸收促肾生长刺激因子。因此，细胞系RK - 13具有吸附促肾生长因子的受体，但无法对生长刺激过程进一步作出反应。促肾生长刺激因子热不稳定，不能被孔径达12,000分子量的透析管透析。因此，促肾生长因子似乎是一种大分子，可能是一种蛋白质。
