镉对大鼠肾皮质的氧化损伤及乙酰半胱氨酸的保护效应

Protective effect of N-acetylcysteine against oxidative damage caused by cadmium on kidney cortex of rat

通过饮水对大鼠进行了镉染毒(Cd 50 mg/L)和乙酰半胱氨酸(NAC)保护(Cd 50 mg/L+NAC1 g/L)试验,8周后检测肾皮质中抗氧化指标和微量元素含量变化,观察其超微结构,以探讨镉对肾的毒性损伤及NAC的保护效应。结果显示,与对照组相比,镉染毒组及NAC保护组肾皮质中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性和还原型谷胱甘肽(GSH)含量显著或极显著(P<0.05或P<0.01)降低,丙二醛(MDA)含量显著或极显著(P<0.05或P<0.01)升高,肾皮质中的铜、硒、锌含量显著降低(P<0.05)。与染毒组比较,NAC保护组肾皮质SOD、GSH-Px活性和GSH含量显著升高(P<0.05);肾皮质铜、锌、硒含量无显著差异(P>0.05)。超微结构观察发现,镉染毒使肾皮质中的细胞核仁破碎溶解,线粒体肿胀变形,部分嵴断裂;NAC保护组病理变化不明显,表明NAC对镉暴露所致的肾毒性损伤具有一定的保护效应。

Through cadmium chloride exposure test（Cd 50 mg/L） and/or protective test by N-acetylcysteine（NAC 1 g/L）, the two compounds were added into drinking water to administered rats for eight weeks. Antioxidant indexes,contents of trace elements（Cu,Zn,Se） in kidney cortex and cortical ultrastructure were detected to investigate the toxicological effects of cadmium on the kidney of rats and the protective effect of NAC against the toxicological effects. Activities of superoxide dismutase（SOD） and glutathione peroxidase（GSH-Px）,contents of reduced glutathione（GSH） in the Cd group and the CD＋NAC group were decreased significantly,contents of malondialdehyde（MDA） in between the two groups were increased remarkably, but contents of copper, zinc and selenium were decreased significantly, as compared these with the corresponding indexes in the control group. Activities of SOD and GSH-Px,and contents of GSH in the Cd＋NAC group were significantly higher than those in the Cd groups,but contents of Cu,Zn and Se in the Cd＋NAC group were not significantly different from those in the Cd group. The nucleoli were damaged with crush and salvation, mitochondria were damaged with swelling and cristae fragmentation in the Cd group by uhrastructural observation. The pathological changes in the Cd＋NAC group were not obvious. It indica ted that NAC could reduce lipid peroxidation and had protective effect on Cd-induced nephrotoxicity.