摘要
目的探讨褪黑素对肾缺血再灌注损伤大鼠肾脏的保护作用及其机制。方法通过无创血管夹夹闭双侧肾动静脉建立大鼠肾缺血再灌注模型,将实验大鼠随机分为假手术组、缺血再灌注组、褪黑素5mg组、褪黑素10mg组和VC组,检测再灌注后6h和24h各组大鼠血清尿素氮(serum urea nitrogen,SUN)和肌酐(serum creatinine,Scr),肾脏线粒体活力、超氧化物歧化酶(superoxide dismutase,SOD)活性、总三磷酸腺苷(ATP)酶活性、丙二醛(malondialdehyde,MDA)含量、Bax、Bcl-2水平,一氧化氮(nitric oxide,NO)含量及一氧化氮合酶(endothelial nitric oxide synthase,eNOS)表达。结果褪黑素5mg、褪黑素10mg及VC组再灌注后6h及24h的血清SUN与缺血再灌注组相比明显降低(t值分别为6h后3.154,3.268,3.415,24h后3.864,4.327,4.586;P值分别为6h后0.032,0.029,0.014;24 h后0.006,0.005,<0.001),Scr与缺血再灌注组相比亦明显降低(t值分别为6h后3.021,3.215,3.534,24h后3.856,4.026,721;P值分别为6h后0.037,0.026,0.012;24h 0.007,0.003,<0.001),肾脏线粒体MDA含量明显降低(t值分别为6h后4.241,5.386,6.352,24h后5.436,6.174,6.053;P值分别为6h后0.004,0.001,<0.001,24h后<0.001,<0.001,<0.001);褪黑素5mg、褪黑素10mg及VC组再灌注后6及24h与缺血再灌注组相比的线粒体活力明显升高(t值分别为6h后1.894,3.762,3.758,24h后0.864,4.143,3.972;P值分别为6h后0.097,0.016,0.017,24h后0.247,0.008,0.011)、SOD活性明显升高(t值分别为6h后16.154,19.637,18.026,24h后15.587,18.596,P值分别为6h后<0.001,<0.001,<0.001,24h后<0.001,<0.001,<0.001)、总ATP酶活性与缺血再灌注组相比均明显升高(t值分别为6h后4.361,5.397,5.403,24h后3.327,4.832,4.851;P值分别为6h后0.004,<0.001,<0.001,24h后0.031,<0.001,<0.001)。上述差异均有统计学意义。结论缺血前和再灌注早期给予褪黑素,可有效减轻肾缺血/再灌注损伤(renal ischemia/reperfusion injury,RIRI)大鼠肾损伤,改善肾功能。其机制可能与其保护线粒体功能,增加抗氧化酶活性,增加保护性NO的含量,减少细胞凋亡等作用有关。
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单位保定市第一中心医院