过度训练致急性肾损伤大鼠肾组织胰岛素样生长因子的表达及其意义

The Effect of IGF-Ⅰ on Overexercise Induced Acute Kidney Injury

目的:研究过度训练致急性肾损伤大鼠肾组织胰岛素样生长因子(IGF-Ⅰ)的表达及其意义。方法:将40只雄性Wistar大鼠按随机数字表法分为对照组(CN)、力竭运动组(ES)。CN组为安静对照;ES组又根据力竭后恢复时间分为力竭后即刻(ESI)、力竭后6h(ES6h)、力竭后12h(ES12h)和力竭后24h(ES24h)。采用大鼠游泳至力竭建立过度训练模型。应用全自动生化仪检测肾功能;免疫组织化学法检测肾组织IGF-I、Bcl-2的表达;TUNEL法检测肾组织细胞凋亡;用图像分析系统测定肾组织凋亡细胞、Bcl-2表达的平均吸光度。结果:力竭即刻大鼠血尿素氮和肌酐明显升高(P<0.05),力竭后6h达高峰(P<0.05),于力竭后24h恢复正常。力竭即刻大鼠肾组织IGF-1蛋白表达明显减弱(P<0.05),之后逐渐增强,于力竭后12h恢复到安静对照组水平(P>0.05)。力竭后12hBcl-2表达减弱(P<0.05),于力竭后24h恢复至正常水平(P>0.05)。TUNEL法显示,过度训练大鼠肾组织凋亡细胞主要分布在肾小管上皮细胞,于力竭后即刻、6h及24h肾小管上皮细胞凋亡数呈进行性增多(P<0.01)。结论:IGF-I可通过改善过度运动后肾脏的血流动力学,同时抑制肾脏组织细胞凋亡发挥其对肾脏的保护。

Objective：To investigate the expression of IGF-Ⅰ in different periods after exhausting swimming and explore the relationship of IGF-Ⅰ and acute kidney injury.Methods：Forty male rats were randomly divided into two groups：control group （CN,n=8）and exhaustive swimming group（ES）,and the exhausting swimming group were divided into four groups depending on the time after exhausting swimming （immediate,6 hours,12 hours and 24 hours;ESI,ES 6 h,ES 12 h and ES 24 h）.We established the rat kidney injury model by exhausting swimming.We first examined the kidney function including creatinine and urea nitrogen by automatic biochemical analyzer.The expressions of IGF-Ⅰ and Bcl-2 were detected by immunol histochemistry.The apoptosis of kidney was detected by TUNEL stain.Results：The serum concentration of Scr and BUN was higher than that of in control group after exhausting swimming and returned to normal in ES 24 h.The expression levels of IGF-Ⅰ decreased in ESI and enhanced in ES 12 h.The expression levels of Bcl-2 decreased in ES 12 h and enhanced in ES 24 h.The cell numbers of apoptosis also increased gradually after exhausting swimming.Conclusion：Conclusion IGF-Ⅰ can improve the hemodynamics of kidney and inhibit renal cell apoptosis so to play a protecting role in acute kidney injury caused by overexercise.