六氯苯对大鼠机体氧化损伤和抗氧化酶活性的影响

目的 研究六氯苯（HCB）对大鼠的毒性作用,探讨HCB中毒的氧化应激机制.方法 2个染毒组分别以含HCB 2.5%（低剂量组）、20.0%（高剂量组）的饲料染毒大鼠14 d,测定血清中碱性磷酸酶等11项血清学指标;测定大脑（皮层、海马）、肝脏和血清中丙二醛（MDA）水平、总超氧化物歧化酶（T-SOD）、过氧化氢酶（CAT）和谷胱甘肽过氧化物酶（GSH-Px）活力.结果 （1）高剂量HCB染毒组大鼠大脑皮层、海马、肝和血清中MDA含量均高于对照组,低剂量染毒组海马和血清中MDA也较对照组明显增加,差异有统计学意义（P＜0.01或P＜0.05）.（2）2个剂量组大鼠大脑皮层和海马中T-SOD活力明显增加,与对照组比较,差异有统计学意义（P＜0.01）;但高剂量组大鼠血清T-SOD活力却明显降低,与对照组比较,差异有统计学意义（P＜0.01）.（3）高剂量染毒组大鼠海马CAT活力高于对照组,差异有统计学意义（P＜0.01）.（4）高剂量染毒组大鼠大脑皮层、海马和低剂量染毒组海马中GSH-Px活力高于对照组,差异有统计学意义（P＜0.01）,但两组大鼠肝脏中GSH-Px活力却明显降低,与对照组比较,差异有统计学意义（P＜0.01）.（5）2个剂量染毒组大鼠血清白蛋白、总胆固醇都较对照明显增加,而血清碱性磷酸酶活力却明显降低,与对照组比较,差异有统计学意义（P＜0.01）.结论 HCB可导致大鼠机体氧化损伤、抗氧化酶活力改变,氧化应激是其重要的毒作用机制.

Toxicity and oxidative stress on rats by hexachlorobenzene

OBJECTIVE: To study the toxicity on rats by hexachlorobenzene (HCB), and to explore the role of oxidative stress in the mechanism of HCB intoxication. METHODS: SD female rats were fed on a powdered diet containing 0.25 per thousand or 2.00 per thousand HCB for 14 days. The content of malondialdehyde (MDA) and the activity of total-superoxide dismutase (T-SOD), catalase (CAT) and glutathione peroxidase (GSH-PX) in cerebral cortex, hippocampus, liver tissue and serum were determined. Eleven biochemical indicators including alkaline phosphatase (ALP) were surveyed. RESULTS: (1) MDA levels in cerebral cortex, hippocampus, liver and serum of the high dosage group rats and that in hippocampus and serum of the low dosage group were significantly higher than that of the control group. (2) The activity of T-SOD was increased in cerebral cortex and hippocampus of the rats in both groups (P < 0.01), but decreased in the serum of the high dosage group (P < 0.01). (3) The activity of CAT was also increased in the hippocampus of rats in the high dosage group. (4) In cerebral cortex and hippocampus of the rats in the high dosage group and in the hippocampus of the rats in the low dosage group, the activity of GSH-PX was significantly higher compared with the control group. However, in liver of both dosage groups, the activity of GSH-PX was decreased (P < 0.01). (5) The activity of serum alkaline phosphatase of both dosage groups was also decreased, but the contents of both serum albumin and total cholesterol were significantly higher than those of the control group (P < 0.01). CONCLUSION: HCB can induce enhanced lipid peroxidation on SD rats, and the oxidative stress plays an important role in the mechanism of neurotoxicity and hepatotoxicity.