Takeda T
Third Department of Internal Medicine, Kinki University School of Medicine, Osaka, Japan.
Nihon Jinzo Gakkai Shi. 1996 Nov;38(11):493-501.
To clarify the development of tubular necrosis and its healing process in ischemic renal failure observing degeneration, necrosis, cell proliferation and the involvement of apoptosis in the renal tubular epithelial cells before and after renal ischemia in rats through morphological examination. Eight week-old male rats were used for this study. The model for acute renal failure was by obstruction of bilateral renal arteries and veins for 45 minutes in several intervals (0 hr, 1 hr, 3 hr, 6 hr, 12 hr, 24hr, 48 hr, 96 hr, 1 week, 2 weeks and 4 weeks) each following reperfusion. Urinary beta 2-microglobulin (BMG) levels were measured to evaluate renal tubular function. In evaluating tubular necrosis and cell proliferation, observations of renal tubular tissue were made serially by use of light microscopy and immunological staining of proliferating cell nuclear antigen (PCNA) and bromodeoxyuridine (BrdU), respectively. The number of nuclei in the proximal tubular epithelium/circumference of the basement membrane (n/BM index) was calculated using a tissue measuring device. Transmission electron microscopy and the TdT-mediated dUTP-biotin nick end labeling (TUNEL) methods were used as indices of apoptosis. Maximal BMG values were obtained 24 hours after ischemia when injury in the proximal tubular epithelium was most prominent. The maximal number of PCNA and BrdU-positive cells were obtained 24 hours after ischemia and thereafter gradually decreased. The n/BM index in the disorder group was significantly increased 96 hours and 1 week after ischemia (p < 0.001). Electron microscopy revealed nuclear fragmentation and apoptosis in the tubular area indicating that there were significant differences. The number of positive cells for in situ nick end labelling increased 24 hours and 2 weeks after ischemia, exhibiting a two peak curve. However, the number of positive cells significantly decreased 4 weeks after ischemia. In the proximal kidney tubules damaged by reperfusion after ischemia, epithelial hyperplasia developed 3 to 6 days after the most active period of S-phase cells was noted. Thereafter, a decreasing number of epithelial cells was observed. It seemed that the decreasing number of these cells had been produced by apoptosis detected 2 weeks after ischemia.
通过形态学检查观察大鼠肾缺血前后肾小管上皮细胞的变性、坏死、细胞增殖及凋亡情况，以阐明缺血性肾衰竭时肾小管坏死的发展及其愈合过程。本研究采用8周龄雄性大鼠。急性肾衰竭模型通过多次间歇性阻断双侧肾动脉和静脉45分钟（分别在再灌注后的0小时、1小时、3小时、6小时、12小时、24小时、48小时、96小时、1周、2周和4周）建立。检测尿β2-微球蛋白（BMG）水平以评估肾小管功能。在评估肾小管坏死和细胞增殖时，分别使用光学显微镜和增殖细胞核抗原（PCNA）及溴脱氧尿苷（BrdU）免疫染色对肾小管组织进行连续观察。使用组织测量装置计算近端肾小管上皮细胞核数/基底膜周长（n/BM指数）。采用透射电子显微镜和TdT介导的dUTP生物素缺口末端标记（TUNEL）法作为凋亡指标。缺血24小时后，当近端肾小管上皮损伤最为明显时，BMG值达到最大。缺血24小时后PCNA和BrdU阳性细胞数量最多，此后逐渐减少。紊乱组的n/BM指数在缺血96小时和1周后显著升高（p<0.001）。电子显微镜显示肾小管区域有核碎裂和凋亡，表明存在显著差异。原位缺口末端标记阳性细胞数量在缺血24小时和2周后增加，呈双峰曲线。然而，缺血4周后阳性细胞数量显著减少。在缺血后再灌注损伤的近端肾小管中，在S期细胞最活跃期后的3至6天出现上皮增生。此后，观察到上皮细胞数量减少。似乎这些细胞数量的减少是由缺血2周后检测到的凋亡所致。
