铁负荷大鼠肝脏及脑组织脂质过氧化相关研究

Influences of iron overload on lipid peroxidation in liver and brain of rats

目的 研究铁负荷对大鼠肝脏及脑组织的脂质过氧化反应的影响 ,以及具抗氧化作用的维生素E和β -胡萝卜素对铁负荷所产生影响的作用。方法 将 80只雄性Wistar大鼠按体重随机分为 8组 ,前 4组给予的饲料铁浓度分别为 5 0 ,2 0 0 ,35 0和 5 0 0mg/kg饲料。后 4组饲料铁浓度分别与前 4组相同 ,但同时在饲料中补充抗氧化剂 [维生素E10 0mg/kg饲料、β-胡萝卜素 2 5mg/ (kg·bw) ],喂养 8周。实验结束时 ,测定血清铁 ,血清维生素E(VE)、维生素A(VA) ,肝和脑匀浆中丙二醛、超氧化物歧化酶和谷胱甘肽过氧化物酶。结果 铁负荷显著增加了肝脏丙二醛水平 ;肝脑各组谷胱甘肽过氧化物酶活性应激性增加 ,VE、VA含量下降。加入维生素类抗氧化剂可降低肝脏及脑组织中丙二醛水平。结论 铁负荷可促进肝脏及脑组织的脂质过氧化反应 ,维生素类抗氧化剂可能通过非酶促反应体系发挥作用 ,抑制上述改变。

Objective To explore the influences of iron overload on lipid peroxidation in liver and brain of rats and the inhibiting effects of antioxidant vitamins including vitamin E and β carotene on the influence induced by iron overload. Methods 80 male Wistar rats were randomly divided into 8 groups according to the weight,the diets of the former 4 groups differed only in iron concentration:50,200,350 or 500?mg/(kg·diet).The diets of the latter 4 groups were consistent with the former 4 groups respectively,but complemented with vitamin E[100?mg/(kg·diet)] and β-carotene[25?mg/(kg·bw)] at the same time .After 8 weeks,the indexes were determined including serum iron,blood lipid (including total cholesterol TC,triglyceride TG,high density lipoprotein HDL,low density lipoprotein LDL),vitamin E,vitamin A and oxidized low density lipoprotein(OX-LDL) in serum;maglonydiadehyde (MDA),the activities of superoxide dismutase (SOD) and glututhione peroxidase (GSH-Px) in liver and brain homogenate. Results Iron overload increased the levels of MDA in liver significantly.The activity of GSH-Px in liver and brain increased irritably and the contents of vitamin E and vitamin A decreased significantly.Complementing antioxidant vitamins caused the levels of MDA in liver and brain to decrease compared with those of the corresponding iron overload groups. Conclusion Iron overload could promote the lipid peroxidation reaction in liver and brain.Antioxidant vitamins may play a role through nonenzyme reactive system to inhibit the above changes.