摘要
目的观察糖尿病仓鼠心肌血管紧张素Ⅱ(ATⅡ)含量,糜蛋白酶和血管紧张素转换酶(ACE)基因表达变化,探讨糜蛋白酶和ACE在糖尿病心肌病变发生中的作用。方法测定正常对照(NC)组(n=10)和糖尿病(DM)组(n=10)仓鼠血浆和心肌ATⅡ含量;荧光定量PCR检测心肌糜蛋白酶和ACE基因表达;观察心肌Ⅰ、Ⅲ型胶原含量变化;测定血糖、糖化血清蛋白、血脂和胰岛素水平。结果与NC组相比,DM组仓鼠心肌Ⅰ、Ⅲ型胶原表达量分别为NC组的2.71和1.68倍,且Ⅰ/Ⅲ型胶原比值明显升高;心肌局部ATⅡ含量显著升高;糜蛋白酶基因表达显著高于NC组,而ACE基因表达在两组间差异无统计学意义。结论糖尿病仓鼠心肌病变时心肌局部升高的ATⅡ可能主要来源于糜蛋白酶途径,抑制糜蛋白酶的表达或活性可能对糖尿病心肌病变具有治疗价值。
Objective To investigate the changes in the content of angiotensin Ⅱ （AT Ⅱ ） and the gene expressions of chymase and angiotensin-converting enzyme （ACE） in diabetic hamsters＇ heart, so as to understand the role of chymase and ACE in the development of diabetic cardiomyopathy. Methods ATⅡ levels in plasma and heart were determined in normal control group （n= 10） and diabetic group （n = 10）. Gene expressions of chymase and ACE were detected by using fluorescent quantitative polymerize-chain-reaction （FQ-PCR）. Levels of type Ⅰ and Ⅲ collagens in heart were measured by immunohistochemical method. Levels of blood glucose, glycated serum protein, insulin and lipid profile were determined. Results Compared with normal control group, levels of collagen Ⅰ and Ⅱ in diabetic group were 2.71 and 1.68 folds higher separately, and the ratio of collagen Ⅰ / collagen Ⅲ was also significantly higher. Level of AT Ⅱ in diabetic hamsters＇ heart was higher than that in normal control. Gene expressions of chymase but not ACE in diabetic group were higher than those in control group. Conclusions Diabetic cardiomyopathy is manifested by elevated level of AT Ⅱ in hearts, which might be produced by route of chymase conversion. And the inhibiting of chymase may have some therapeutic values.
关键词
糖尿病
仓鼠
心肌病变
糜蛋白酶
聚合酶链反应
Diabetes mellitus
Hamster
Cardiomyopathy
Chymase
Polymerase
Chain reaction
