亚慢性铅与镉单独或联合暴露致大鼠氧化损伤作用及α-硫辛酸的保护效应

Oxidative damage of sub-chronic exposure to lead and/or cadmium in rats and the protection of α-lipoic acid

为研究铅、镉单独及其联合暴露对SD大鼠机体的氧化损伤以及α-硫辛酸的保护作用,以300mg/L铅、50 mg/L镉单独或联合采用自由饮水方式染毒SD大鼠,α-硫辛酸保护组在铅、镉自由饮水的同时用α-硫辛酸（50 mg/kg剂量）灌胃,12周后测定血清中过氧化氢酶（CAT）、超氧化物岐化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）的活性和丙二醛（MDA）的含量。结果,与对照组相比,各染毒组CAT、SOD、GSH-Px活性极显著降低（P〈0.01）,MDA含量极显著升高（P〈0.01）。与铅、镉单独染毒组相比,铅镉联合染毒组GSH-Px活性显著或极显著降低（P〈0.05或P〈0.01）,SOD和CAT活性降低,但无显著性差异;MDA含量升高,与铅单独染毒组差异显著（P〈0.05）。与对应染毒组相比,染毒的同时添加α-硫辛酸组大鼠血清中CAT、SOD、GSH-Px活性和MDA含量均有所恢复,除镉与α-硫辛酸联合组MDA含量差异不显著外,其余组均具有统计学意义（P〈0.05或P〈0.01）。上述结果说明,铅、镉能够导致大鼠氧化损伤,α-硫辛酸在一定程度上能够有效缓解铅、镉引起的氧化损伤,起到一定的保护作用。

In order to evaluate the oxidative damage induced by sub-chronic lead and/or cadmium exposure in SD rats and protective effects of α-lipoic acid,SD rats were exposed to lead（300 mg/L）,cadmium（50 mg/L）,respectively or lead combined with cadmium（300 mg/L＋50 mg/L）as drinking water,the rats of lead and/or cadmium-treated groups were treated with α-lipoic acid（50 mg/kg according to body weight）by intragastric administration simultaneously.After 12 weeks,the activities of CAT,SOD,and GSH-Px and the contents of MDA in serum were measured.In result,compared with the control group,the activities of CAT,SOD and GSH-Px in the lead and/or cadmium-exposed groups all decreased significantly（P〈0.01）,andthe contents of MDA increased significantly（P〈0.01）.Compared with the lead or cadmium group,the activity of GSH-Px in the lead and cadmium combined group was significantly decreased（P〈0.05 or P〈0.01）,and the activity of SOD and CAT decreased,but there was no significant difference,and the content of MDA increased,which was significantly different from lead group（P〈0.05）.Compared with the corresponding exposure groups,the activities of CAT,SOD,and GSH-Px and the contents of MDA in serum of rats exposed to lead and/or cadmium with α-lipoic acid were partially recovered.In addition to the MDA of the cadmium and α-lipoic acid combined group was not significantly different,the remaining groups were statistically significant（P〈0.05 or P〈0.01）.The results indicated that lead and cadmium can cause oxidative damage to rats,but α-lipoic acid can effectively alleviate the oxidative damage caused by lead and cadmium to some extent and supply some protective effects.