2型糖尿病大鼠主动脉内膜早期超微结构改变与氧自由基关系

Relationship between Early Ultrastructural Changes of Aortic Intima and Oxidative Free Radicals in Diabetic Rats

目的探讨２型糖尿病大鼠主动脉内膜早期超微结构改变及其与氧自由基关系。方法用比色法对２型糖尿病大鼠血浆脂质过氧化物（ｌｉｐｉｄｓｕｐｅｒｏｘｉｄｅ，ＬＰＯ）、超氧化物歧化酶（ｓｕｐｅｒｏｘｉｄｅｄｉｓｍｕｔａｓｅ，ＳＯＤ）进行了测定，同时电镜下观察实验１０周时２型糖尿病大鼠主动脉内膜早期超微结构改变。结果糖尿病组（Ⅰ组）及单纯肥胖组（Ⅱ组）均有主动脉内膜超微结构改变。对内皮下厚度、内膜损伤评分及内皮下平滑肌细胞层数计数，可见Ⅰ、Ⅱ组内皮下厚度及评分增加，但Ⅰ组更显著，与Ⅱ组比较，差异非常显著（Ｐ＜００１）。与正常组比较，Ⅰ、Ⅱ组ＬＰＯ升高（Ｐ＜００１），Ⅰ组ＳＯＤ下降而Ⅱ组ＳＯＤ升高。结论实验性２型糖尿病大鼠主动脉内膜早期有超微结构改变且这种改变与ＬＰＯ升高及ＳＯＤ下降有密切关系。

Objective To investigate the early ultrastructural changes of aortic intima and its relationship with oxidative free radicals.Mehtods The serum lipid peroxidates (LPO) and superoxide dismutase(SOD) levels measured by chromatography in rats with type 2 diabetes mellitus were compared with those in fatty and normal rats.The ultrastructure of aortic intima in rats at ten weeks were observed under electron microscopy.[WT5”HZ]Results The ultrastructural changes of aortic intima could be observed both in diabetic group (Group I ) and fatty group (Group II ). It was found that both diabetic and fatty rats had wider subendothelial space,higher scores of endothelial injury and more layers of smooth muscle cells than those in normal rats. So did Group I compared with those in Group II. Serum LPO levels in diabetic and fatty rats were higher than that in normal rats.Serum SOD level was also higher in fatty rats but lower in diabetic rats.Conclusion Rats with type 2 diabetes mellitus was found to have early ultrastructural changes of aortic intima which was related to the increase of LPO and decrease of SOD.