【摘要】 目的通过胸腺质量及胸腺指数增龄变化,血清超氧化物歧化酶(SOD)以及丙二醛(MDA)的测定,系统地探讨衰老期SOD酶活性与MDA含量变化的规律及胸腺质量、胸腺指数增龄变化。方法大鼠按年龄分组,测定其胸腺质量及体质量大小,取血并测定各组血清中SOD、MDA含量。结合光镜、电镜结构的形态学变化进行分析。结果测定结果显示,随着年龄的增加,胸腺指数明显下降。老年组血清中的MDA水平升高,而SOD含量则明显下降。同时胸腺组织的光、电镜观察呈胸腺皮质变薄,胸腺细胞稀疏,皮、髓质分界不清;大量的脂肪、纤维代替了部分凋亡的胸腺细胞,线粒体肿胀,嵴减少,出现大小不等的空泡,核固缩。结论随着年龄增加,个体体重增加,胸腺内分泌微环境功能下降,SOD活性和含量减少;无法清除血清中不断产生的自由基和MDA而出现一系列细胞凋亡,胸腺萎缩退化,胸腺指数下降。更多还原

【Abstract】 Objective To explor the relation between aging and thymus indices.based on changes of thymus weight and thymus indices in rats with aging and SOD activity of RBC and the content of serum MDA.Methods According to their ages,the rats were divided into three groups randomly.Thymus weight,thymus indices,SOD activity and MDA content were determined.In addition,morphologic changes of thymic structure were observed under high power and electron microscopes.Results The thymus indices decreased with age increase,and SOD activity markedly decreased,while MDA content was enhanced with aging.The thymic cortex became thin.The thymocyte density ratio of cortex to medulla decreased with aging,and there was no distinguished line between cortex and medulla with age increase under high power microscope.A great number of fat and fibrins were replaced by vacuole,thymocyte and other structure.The apoptotic thymocytes and their mitochondria became swollen and vacuolized with the crista reduction and a large number of vacuoles appeared.The nuclus became condensed and marginated.Conclusion Thymus indices decrease with body weight increasing.The function of microenvironment of endocrine in thymus is decreased.SOD activity markedly decreases,so that the free radicals and MDA can not be removed develeping from RBC,which might cause the thymocyte apoptosis and thymus vacuole and thymus indices decrease.更多还原