乌司他丁对肾毒性大鼠肾小管上皮细胞凋亡及Caspase-3蛋白的影响

Effects of Ulinastatin on the tubular epithelial cell apoptosis and Caspase-3 in rat with contrast medium-iduced nephrotoxicity

目的研究乌司他丁(Ulinastatin,UTI)对造影剂肾毒性大鼠肾小管上皮细胞凋亡和凋亡相关基因半胱氨酸天冬氨酸蛋白酶3(Caspase-3)蛋白表达的影响。方法将大鼠随机均分为正常组、模型组、UTI低、高剂量组(2.5×104、5.0×104IU·kg-1)。除正常组外,其余各组均于大鼠后腿深部肌肉注射25%甘油(10 m L·kg-1),48 h后于尾静脉iv 76%泛影葡胺(10m L·kg-1)造模。UTI组大鼠分别在注射造影剂24、48 h后给药,测定血清中胱抑素C(Cys C)和肌酐(Scr)的水平;光镜下观察肾组织的病理学变化,进行Paller评分;TUNEL染色检测肾小管上皮细胞的凋亡;免疫组化法检测Caspase-3蛋白的表达。结果模型组大鼠的肾小管上皮细胞出现明显水肿、空泡变性和颗粒变性、刷状缘丢失以及肾小管扩张等;与正常组比较,模型组的血清Cys C和Scr水平、Paller评分显著升高,肾小管上皮细胞凋亡增多,Caspase-3蛋白表达显著上调,与模型组比较,UTI组的血清Cys C、Scr水平明显降低,肾组织损害减轻、Paller评分下降,肾小管上皮细胞Caspase-3蛋白的表达显著下调,细胞凋亡率明显降低。结论 UTI可下调大鼠肾小管上皮细胞Caspase-3蛋白的表达,抑制肾小管上皮细胞的凋亡,对造影剂肾毒性大鼠起保护作用。

OBJECTIVE To investigate the effects of Ulinastatin（ UTI） on the tubular epithelial cell apoptosis and related geneexpression of Caspase- 3 in rat with contrast medium- iduced nephrotoxicity（ CIN）. METHODS 32 rats were randomly divided into： normal group,model group,low（ 2. 5 × 104IU·kg^- 1） and high（ 5. 0 × 104IU·kg^- 1）. Except the normal group,the rats of other groups were treated with 25% glycerol（ 10 m L·kg^- 1） hind legs deep intramuscular injection,then iv 76% diatrizoate（ 10 m L·kg^- 1）in the tail vein. The UTI was poured into the stomach of rats in the UTI- L and UTI- H group for two days. Abdominal aortic blood samples were collected to determine the concentrations of serum creatinine（ Scr） and cystatin C（ Cys C）. The renal tissues were obtained for microscopic examination,and paller ’s score was recorded,the expression of Caspase- 3 protein in renal tissues were detected by immunohistochemistry method. TUNEL was used to detect the tubular epithelial cell apoptosis. RESULTS In the rats of model group,the histological examination with HE revealed the different extents of acute tubular injury with tubular epithelial cell swelling,vacuolar degeneration,tubular border loss,and tubular dilatation. The levels of serum Cys C,Scr and paller score were obviously increased. The expression of Caspase- 3 in renal tissue was up- regulated. The percentage of tubular epithelial cell apoptosis was significantly increased. In the rats of UTI group,the renal injuries induced by diatrizoate were alleviated. The levels of serum Cys C,Scr and paller score were significantly lower than that of the model group. The expression of Caspase- 3 in renal tissue was down-regulated. The percentage of tubular epithelial cell apoptosis was significantly decreased. CONCLUSION UTI has a protective role against contrast- induced nephropathy in the rats. The mechanism of protective effects may be related to the inhibition of Caspase- 3activity in renal tissue,and consequently reduce renal tubular epithelial cell apoptosis.