Yun G C, Areas J, Yamamoto N, Preuss H G
Department of Medicine (Nephrology Division), Georgetown University Medical Center, Washington, D.C. 20007.
Life Sci. 1988;42(26):2721-7. doi: 10.1016/0024-3205(88)90249-4.
A circulating renotropic factor specific for renal cells has been described in rats. The addition of sera obtained from unilaterally nephrectomized (uni) rats 24h after operation compared to sham-operated (sham) rats augments 3H-thymidine incorporation into the DNA of incubating kidney slices approximately 10%-30%. Attempting to amplify the sensitivity of the assay for this renotropic agent, we replaced slices with primary rat kidney cultures. The assay system was based on one previously used for rabbits. The cultured cells were synchronized in their growth phase by a period of protein-free starvation. Compared to sera from sham rats, sera from uni rats showed significant stimulation of thymidine incorporation into DNA, 35.5% +/- 9.3 (SEM), p less than .0001, at 16 h; 63.3% +/- 10.0 (SEM), p less than .001, at 24 h; and 19.5% +/- 6.5 (SEM), p less than .01, at 48 h post operation. Accordingly, the maximal stimulation at 24 h was greater than that previously found using the kidney slice assay. Measurable renotropic activity occurred earlier and over a shorter duration than in rabbits. Stimulation was similar when a D-valine medium, relatively specific for renal epithelial cells, replaced DME medium. We conclude that growth synchronized, primary rat renal cells in culture verify the presence of a circulating renotropin arising 24 h post uni.
在大鼠中已描述了一种对肾细胞具有特异性的循环促肾生长因子。与假手术（sham）大鼠相比，单侧肾切除（uni）大鼠术后24小时获得的血清添加到培养的肾切片中，可使3H-胸腺嘧啶核苷掺入DNA的量增加约10%-30%。为了提高对这种促肾生长因子检测的灵敏度，我们用原代大鼠肾细胞培养物取代了切片。检测系统基于先前用于兔子的一种系统。通过一段时间的无蛋白饥饿使培养的细胞在生长阶段同步化。与假手术大鼠的血清相比，单侧肾切除大鼠的血清在术后16小时显著刺激了胸腺嘧啶核苷掺入DNA，为35.5%±9.3（标准误），p<0.0001；在24小时时为63.3%±10.0（标准误），p<0.001；在48小时时为19.5%±6.5（标准误），p<0.01。因此，24小时时的最大刺激作用大于先前使用肾切片检测所发现的。可测量的促肾生长活性比在兔子中出现得更早且持续时间更短。当用对肾上皮细胞相对特异的D-缬氨酸培养基取代DME培养基时，刺激作用相似。我们得出结论，培养的生长同步化的原代大鼠肾细胞证实了单侧肾切除术后24小时出现循环促肾生长素。
