【摘要】 为阐明硒缺乏动物自由基代谢与硒缺乏症发病学的关系，以及硒和ＶＥ在自由基代谢中的作用，采用低Ｓｅ（低于０．００１ｍｇ／ｋｇ）、补Ｓｅ（２．０６ｍｇ／ｋｇ）、ＶＥ（１００ｍｇ／ｋｇ）日粮饲喂小鼠，并对血液、肝组织丙二醛（ＭＤＡ）、硒谷胱甘肽过氧化物酶（Ｓｅ－ＧＳＨ－Ｐｘ）、相关微量元素及自由基（ＦＲｓ）水平进行了系统检测。实验发现，硒缺乏动物存在明显的以血液、肝组织ＭＤＡ、ＦＲｓ水平升高、Ｓｅ－ＧＳＨ－Ｐｘ活力下降为特征的自由基代谢紊乱；补硒可显著降低组织内ＭＤＡ、ＦＲｓ水平、提高Ｓｅ－ＧＳＨ－Ｐｘ活性。而补ＶＥ仅表现为使血液、肝组织内ＭＤＡ含量降低；补硒加ＶＥ较之于单纯补硒、ＶＥ可使ＭＤＡ含量下降更为明显。结果表明，自由基代谢紊乱所致的自由基损伤机制是硒缺乏症发病学的重要机制；硒不仅作为Ｓｅ－ＧＳＨ－Ｐｘ必需组分，通过影响过氧化物酶的活性而发挥抗氧化作用，而且它能通过对ＦＲｓ的直接清除发挥抗自由基损伤作用，而ＶＥ主要通过对脂质过氧化反应的抑制作用而发挥对生物膜脂质过氧化的保护作用；硒和ＶＥ通过作用于不饱和脂肪酸过氧化链式反应中的不同段而在抗氧化损伤中发挥协同作用。更多还原

【Abstract】 To clarify the relationship between free radicals metabolism and the pathogenesis of selenium deficiency,and the effects of selenium(Se)and Vitamin E(V E) on free radicals metabolism,120 mice were fed with different diets,which containing less then 0.001 mg/kg Se(Se -),2.06mg/kg Se(Se -+Se),100mg/kg V E (Se -+V E),and 2.06mg/kg Se plus 100mg/kg V E(Se -+Se+V E),respectively.Molonaldehyde(MDA) concentration in serum and liver,Se Glutathione Peroxidase(Se GSH Px) activity of whole blood and liver,relevant mineral elements concentration and free radicals concentration in liver were investigated in different experimental groups.The disorder of free radicals metabolism was found in Se - group,which was characterized by the dramatical increase of MDA,FRs concentration in serum and liver,and marked decrease of Se GSH Px activity in whole blood and liver;The marked rise of Se GSH Px activity and decline of MDA,free radicals concentration in relevant tissues were found after Se supplementation,but only the decrease of MDA concentration was found after V E supplementation;Also the decrease of MDA concentration of serum and liver in Se -+Se+V E group was greater than that in Se -+Se,Se -+V E groups. The results showed that the free radical damage mechanism induced by the disorder of free radicals metabolism might play an important role in the pathogenesis of Se deficiency.The effects of Se on free radicals metabolism included the involvement in the action of scavenging peroxide as a necessary component of glutathione peroxidase,and the antioxidant property through the directly scavenging on free radicals.However,V E was mainly involved in the protection against the lipid peroxidation of biological membranes,acting as potent antioxidant.The results also suggested that Se and V E worked synergistically to protect lipid peroxidation by means of the inhibition/enzymolysis on the chain of peroxidation of unsaturated fatty acid.更多还原