肾小管上皮细胞损伤和再生中的凋亡现象

阐明肾小管上皮细胞损伤及再生过程中细胞凋亡的意义。方法：给Wistar大鼠腹腔注射庆大霉素，分别造成急性和慢性肾小管损伤模型，不同时间宰杀。用原位末端标记法及DNA琼脂糖凝胶电泳观察细胞凋亡，增殖细胞核抗原（PCNA）免疫组化观察增殖情况。将不同浓度的庆大霉素加入培养的大鼠肾小管上皮细胞诱导凋亡。结果：大剂量庆大霉素主要造成肾小管上皮细胞坏死，少量细胞凋亡。小剂量庆大霉素长时间作用以空泡变性、凋亡为主。各个时间点后者的凋亡细胞数均高于前者。肾小管上皮细胞第5天出现再生，第9天达高峰，细胞凋亡于第5天出现第一个高峰，第12天出现第二个高峰，发生于再生高峰之后。体外实验中，小剂量庆大霉素引起较多细胞凋亡，大剂量庆大霉素主要引起细胞坏死。结论：大剂量庆大霉素造成肾小管上皮损伤以坏死为主，小剂量庆大霉素造成肾小管上皮细胞损伤以变性、凋亡为主。凋亡在肾小管上皮细胞再生过程中，有重要的修饰和改建作用。

APOPTOSIS IN INJURY AND REGENERATION OF TUBULAR EPITHELIAL CELLS

Objective: To investigate the apoptosis in injury and regeneration of tubular epithelial cells.Methods: Acute and chronic renal tubular injury in female Wistar rats were induced by intraperitoneally injecting Gentamicin, and sacrificed at different time. Apotosis of rat tubular cells in primary cultures was induced by adding Gentamicin in different concentration. Apoptosis of renal tubular cells was detected with TUNEL technique and DNA agarose gel electrophoresis. The levels of cell proliferation were measured by displaying PCNA. The morphological changes in tubular cells were observed with electron microscopy.Results: Acute tubular injury showed that more cells exhibited necrosis and a few apoptosis. Chronic tubular injury showed mainly cellular degeneration and aoptesis. Apoptosis occured at two phases: associated necrosis phase and saiated regenerative phase. Conclusion: These data suggested Gentamicin in high concentration induced tubular cells necrosis, but that in low concentration induced tubular cells apoptosis and degeneration.Apoptosis plays an important role in remedification of regenerative tubule.