四氯化碳诱导大鼠肾细胞凋亡的研究

STUDY ON THE APOPTOSIS OF RENAL CELLS OF CARBON TETRACHLORIDE INDUCED RATS

目的观察四氯化碳(CCl4)诱导大鼠肾形态结构和肾细胞凋亡的变化。方法将健康雄性Wistar大鼠随机分为对照组、2周CCl4组和6周CCl4组,每组5只。对照组背部皮下注射橄榄油(0.12 ml/100 g鼠重),CCl4组以0.3 ml/100 g鼠重背部皮下注射60%CCl4橄榄油。2周CCl4组和6周CCl4组大鼠分别于实验的第3周和7周的第1 d处死。肾石蜡切片苏木精-伊红染色,光镜观察肾组织形态学,免疫组织化学显示Caspase-3、Bax、TUNEL观察肾细胞凋亡。结果对照组肾小球和肾小管结构均正常。2周和6周CCl4组的肾小球结构正常,2周CCl4组病变较、6周CCl4组肾皮质近端小管管腔狭小,上皮细胞浊肿,空泡变性,微绒毛脱失。对照组和2周CCl4组Caspase-3、Bax免疫组织化学显色未见阳性细胞表达;而6周CCl4组则在近髓质处的皮质内,近端小管上皮细胞的胞质呈现棕黄色阳性反应。TUNEL显色2周CCl4组可见肾皮质内近端小管上皮细胞核和少量的肾小球细胞核呈阳性表达,而6周CCl4组在大量的远曲小管及少量近端小管的上皮细胞核呈阳性表达。结论CCl4诱导性肾损伤大鼠,2周时肾组织的近端小管上皮及少量肾小球毛细血管内皮细胞发生凋亡,而损伤6周时,肾皮质近端小管受损,上皮细胞变性;远曲小管上皮细胞发生凋亡。

Objective To observe the change of renal morphological structure and apoptosis of renal cells. Methods Healthy adult male Wistar rats were randomly divided into control group （ n = 5）, 2 weeks CCl4 group （ n = 5） and 6 weeks CCl4 group （ n = 5） . The control group were injected oily solution with 0.12 ml/100 g rat weight, the CCl4 group were subcutaneously injected 60% carbon tetrachloride oily solution with 0.3 ml/100 g rat weight. At the first day of 3 weeks and 7 weeks, 2 weeks CCl4 group and 6 weeks CCl4 group rats were respectively killed. The morphological structure in renal central section was observed after HE staining. The expressions of Caspase-3 and Bax were detected by immunohistochemistry. The apoptosis of rat renal cells was detected by TUNEL staining. Results The structures of rat renal tubules and corpuscle was normal in the control group. We detected the histological change in proximal tubules in the 6 weeks CCl4 group, tiny tomentums of epithelial cells fell off, cells was vacuolization. The structure of renal corpuscle was normal. The pathological changes of 2 weeks CCl4 group were similar, but relative little and limited. There was no Caspase-3 and Bax positive cell in control group and 2 weeks CCl4 group, but lots of Caspase-3 and Bax positive cells were in 6 weeks CCl4 group, mainly fastened on epithelial cells of proximal tubules near the medulla, and brown granules were mostly located in the cytoplasm. There was no positive cell in control group by TUNEL staining. There were a lot of apoptosis epithehal cells of proximal tubules, renal glomerular also had a few of TUNEL positive cells in the 2 weeks CCl4 group. Apoptosis cells mainly located in the epithelial cells of distal tubules in the 6 weeks CCl4 group, a few of apoptosis epithelial cells were in proximal tubules. Conclusion In carbon tetrachloride induced renal injuried rats, apoptosis cells mainly happened in epithehal cells of proximal tubules in 2 weeks. The apoptosis of epithelial cells of distal tubules presented 6 weeks later.