肾缺血再灌注损伤大鼠肾内AQP2表达水平降低

Decreased expression of AQP2 in the kidney of the rats with renal ischemia-reperfusion injury

目的了解肾脏缺血再灌注损伤(ischemia reperfusion injury, IRI)时肾内水通道蛋白-2(aquaporin 2, AQP2)免疫组织化学表达特点。方法建立大鼠右侧肾IRI 45min模型,随机分为缺血再灌注1d、3d、5d、7d组和假手术1d组,检测尿常规、尿比重、尿素氮、血肌酐;HE染色观察肾脏病理形态学变化;免疫组织化学染色观察IRI时肾脏AQP2表达的变化。结果 IRI后,大鼠出现尿量增多,尿比重降低,血肌酐、尿素氮均增加;HE染色示右侧肾充血,水肿以及肾小管上皮细胞肿胀、坏死和脱落;免疫组织化学染色显示AQP2免疫反应性在右肾降低,左肾增强。肾组织的变化在第7d基本恢复正常。结论肾IRI时肾内AQP2表达降低,可能与IRI后尿量增多、尿比重降低相关。

Objective To investigate the expression changes of aquaporin 2 (AQP2) in renal ischemia reperfusion injury (IRI) by immunohistochemistry. Methods SD rats were randomly divided into 5 groups according to the time of reperfusion:1 day group,3 days group,5 days group, 7 days group and sham operation 1 day group and then were used to establish the animal model of renal IRI on the right side, which meant the rats were subjected to ischemia for 45 min and immediately recover kidney blood perfusion. After the operation, urinalysis was performed. Urine specific gravity, blood urea nitrogen (BUN) and serum creatinine (SCR) were detected. The pathological changes of the kidney tissues were observed by HE staining. The protein expression of AQP2 in renal ischemia reperfusion injury (IRI) was measured by immunohistochemistry. Results After ischemia-reperfusion injury, the amount of urine increased and the urine specific gravity decreased, serum creatinine and blood urea nitrogen levels were elevated. HE staining showed right renal congestion and edema and renal tubular epitheliums were swelling, necrosis and desquamate. Immunohistochemical stain showed that aquaporin-2 expression decreased in the right kidney and increased in the left. These changes generally return to normal in 7 days. Conclusion Renal IRI causes decrease in AQP2 expression in the kidney, which is likely associated with the increase of urine volume and the decrease of urine specific gravity of the rats after the renal IRI.