Miskell C A, Simpson D P
Department of Medicine, University of Wisconsin, Madison.
Kidney Int. 1990 Feb;37(2):758-66. doi: 10.1038/ki.1990.43.
Using 3H-thymidine (3H-T), we examined DNA synthesis in rats subjected to either uninephrectomy (UNI), five-sixths nephrectomy (R) or sham (S) surgery. Twenty-four, 48, or 72 hours later, animals were infused with 14C-inulin, PAH and 3H-T and clearances obtained. Prior to sacrifice, India ink was injected for glomerular counting. By 24 hours, glomerular filtration rate per nephron was significantly increased in UNI. However, in R, glomerular filtration rate per nephron was significantly lower than S until 72 hours. Total micrograms DNA per nephron was unchanged in UNI but significantly increased in R compared to S at all times. 3H-T incorporation into DNA was twice as great in UNI as in S was over five-fold greater at 24 hours in R than in S; this marked increase persisted in R at 48 and 72 hours. Autoradiographs confirmed that DNA was synthesized predominantly by renal tubular cells and not infiltrating cells. These results indicate that hyperplasia in compensatory renal growth is related to the quantity of tissue removed and that, in the remnant kidney, DNA synthesis precedes the compensatory increase in glomerular filtration rate per nephron.
我们使用³H-胸腺嘧啶核苷（³H-T），检测了接受单侧肾切除（UNI）、六分之五肾切除（R）或假手术（S）的大鼠的DNA合成情况。24、48或72小时后，给动物注入¹⁴C-菊粉、对氨基马尿酸（PAH）和³H-T，并测定清除率。在处死前，注射印度墨汁以进行肾小球计数。到24小时时，UNI组单个肾单位的肾小球滤过率显著增加。然而，在R组中，直到72小时，单个肾单位的肾小球滤过率都显著低于S组。UNI组单个肾单位的DNA总微克数没有变化，但与S组相比，R组在所有时间点的DNA总微克数均显著增加。³H-T掺入DNA的量在UNI组是S组的两倍，在R组24小时时比S组高出五倍多；这种显著增加在R组48小时和72小时时仍然存在。放射自显影片证实，DNA主要由肾小管细胞而非浸润细胞合成。这些结果表明，代偿性肾生长中的增生与切除的组织量有关，并且在残余肾中，DNA合成先于单个肾单位肾小球滤过率的代偿性增加。
