金属硫蛋白和a-硫辛酸对糖尿病大鼠心肌作用的研究

目的 研究金属硫蛋白及旷硫辛酸对糖尿病大鼠心肌细胞形态学的影响及对凋亡的干预。方法32只SD大鼠分为正常对照（NC）组，STZ诱导糖尿病（DM）组，糖尿病＋金属硫蛋白（MT）组和糖尿病＋硫辛酸（ALA）组。比较各组心脏重量／体重比值，透射电镜下观察各组心肌细胞超微结构，TUNEL法检测心肌组织凋亡。结果与NC组相比，DM组心脏重量明显下降（P〈0．01），MT组上升（P〈0．05），TUNEL法显示DM组阳性染色细胞数最多，NC组阳性染色细胞数最少（P〈0．01），MT组阳性染色细胞数较DM组明显减少（P〈0．05）。结论金属硫蛋白对糖尿病大鼠心肌组织保护作用优于旷硫辛酸，可能通过抑制心肌细胞凋亡起作用。

The effects of metaliothionein versus a-lipoic acid on myocardial tissue of diabetic rats

Objective To compare the effects on apoptosis of myocardial tissue of diabetic rats between metallothionein and a-lipoic acid. Methods Diabetic rats model （24, male） were induced by injection of streptozotocin （STZ） （65 mg/kg, intraperitoneal）. They were divided into 3 groups： MT group/-n=8, metallothionein, 5 g（kg ·d）, ALA group n=8, a-lipoic acid, 100 mg/（kg ·d）, DM group（n：8）. There were 8 normal rats as control. The myocardial cells were detected by transmission electron microscope. The myocardial tissues were analyzed by TUNEL for apoptosis. Results Compared with the NC group, the heart weight of the DM group was decreased significantly -（1. 559q- 0. 101） vs （1. 265==0. 237） g,P〈0. 011, while that of the MT group was increased significantly -（1. 559 ±0. 101） vs （1. 668±0. 171） g,P〈0.05], The apoptosis index of DM group was higher than that of the NC group （P〈0. 01）. The index of MT group was lower than that of the DM group（P〈0. 05）. Conclusion The better benefit of metallothionein than a-lipoic acid for diabetic myocardial tissue may depend on inhibiting the apoptosis of myocardial cells.