自由基在二恶英毒性机理中的作用及其清除剂的保护效应研究

Studies on the Role of Free Radicals in TCDD Toxicitive Mechanism and Pretective Effect of Eliminator

本试验使用清洁级SD大鼠54只,雌雄不限,体重250±20 g,随机分成3组:Ⅰ组为正常对照组,腹腔注射等量0.3 m lM DSO;Ⅱ组为二恶英(TCDD)染毒组,染毒剂量为50μg/kg;Ⅲ组为染毒TCDD加自由基清除剂保护组。每组18只,TCDD溶于二甲基亚砜(DM SO)中,质量浓度为25μg/m l。分别在24、48和72 h后,处死动物,制备肝匀浆组织和肝线粒体膜,通过对SD大鼠肝脏中抗氧化酶还原型谷胱苷肽(g lu tath ione,G SH)、总抗氧化能力(tota l an tiox idative capac ity,T-AOC)、还原型谷胱苷肽过氧化物酶(g lu tath ione perox idase,G SH-Px)、超氧化物歧化酶(superox ide d im u tase,SOD)活性及丙二醛(m a lond ia ldehyde,M DA)含量变化和线粒体膜磷脂酶A2(PLA2)活性变化的研究,从自由基角度揭示TCDD的毒性机制及清除剂G的保护效应。TCDD染毒急性清洁级SD大鼠后,诱生过多的自由基,消耗机体内酶性和非酶性的自由基清除剂,引起机体内自由基积累对肝脏造成脂质过氧化作用,膜酶受损,致使整个细胞稳态被扰乱;清除剂G可以通过减少自由基的大量产生而间接抑制PLA2活性的增强,保护膜的结构和功能,具有稳膜效应,减轻TCDD对膜的损伤,并维持磷脂组分的稳定。

This experiment used 54 SD big rats in clean level, which were female or male ,the weight was about （250± 20）g, 54 healthy SD big rats were randomly divided into 3 groups： Group Ⅰ were control group, which were injected abdominaly with the same amount of dose 0. 3 ml MDSO; Group Ⅱ were the TCDD infected group, at the dose of 50 microgram/kg;Group Ⅲ was infected group added the free radicals disinfective medicine. 18 rats for each group. TCDD dissolved in DMSO, the liquor＇s proportion was 25 mierogram/ml. SD big rats Separately were killed after 24 48 and 72h to Prepare the liver refining organization and the mitochondria membrane ,according to the activities changes of antioxidase SOD, GSH,GSH-Px as well as MDA content in SD big rats liver, the liver mitochondria membrane and the mitochondria membrane phosphatide enzyme A2activity changed studying, In order to promulgate the UCDD toxic mechanism as well as the protective effect of scavenger G from the aspects of free radicas. TCDD lure redundant free radicals to consumed the enzymatic and unenzmatic FRs mundificant of organism,to cause hepatic lipid peroxidation in SD rats after acute exposure, membases were damaged. And then disturbed integra steady state of cells. Scavenger G could indirectly cut down the activity of ATPase and indirectly shut down the activity of PLA2through scavenging TCDD to lure redundant ree radicas, protect the constitution and function of cell membrane, free radical scavenger had the effectiveness of steading membrane, membrane damage of lessening,and maintained stabilization of phospholipids ingredient.