实验性Ⅱ型糖尿病大鼠主动脉早期超微结构改变及影响因素

本实验测定了实验性Ⅱ型糖尿病大鼠血脂、血浆过氧化脂质及超氧化物歧化酶,观察了10周时大鼠主动脉超微结构的改变。结果表明:糖尿病组及单纯肥胖组大鼠均有主动脉内膜病变,前者较明显。与对照组大鼠比较,前二者过氧化脂质、甘油三脂及低密度脂蛋白胆固醇均增高,而高、低密度脂蛋白胆固醇比值下降,差异非常显著(p<0.01),糖尿病组大鼠超氧化物歧化酶下降而单纯肥胖组大鼠则升高。以上结果提示,实验性Ⅱ型糖尿病大鼠主动脉内膜有早期超微病理改变,这种病变与过氧化脂质升高及超氧化物歧化酶活性下降有关。与脂代谢紊乱也有一定的关系。

Early Ultrastructural Changes of Aorta and the Possible Cause in Experimental Non-insulin-dependent Diabetes Mellitus Rats

The ultrastructural changes of aorta in adult Wistar rats with streptozotocin(SZ) induced non-insulin-dependent diabetes mellitus were observed.Meanwhile, plasma lipid,lipid peroxides(LPO) and supperoxide dismutase(SOD) levels were measured.The results showed that both diabetic group and fat group had ultrastructural pathologic changes in their wall and the situation in diabetic group is severe than in fat group and the differences in subendothelial depth,numbers of layers of smooth muscle cells in intima and points scored for damage in intima were very significant(p< 0. 01). The plasma triglycerides, total cholesterol and low density lipoprotein cholesterol levels were increased(p< 0. 01), but high density lipoprotein cholesterol/low density lipoprotein cholesterol was decreased(p<0. 01)in fat group and diabetic group. The plasma LPO levels in diabetic group and fat group were increased(p<0. 01), the plasma SOD levels in diabetic group was decreased but increased in fat group(at the forth week, p<0.05; at the tenth week,p<0. 01). The results above indicate that the experimental SZ-induced non-insulin-dependent diabetes mellitus rats rats have the early ultrastructural pathologic changes in aorta wall,which would be associated with the increase of LPO, decrease of SOD and the disorders of lipid metabolism.