Study on cardiomyopathy complicated with type 2 diabetes mellitus in rats / 中华老年医学杂志

ABSTRACT

Objective To study the development of cardiomyopathy complicated with type 2 diabetes mellitus in the rats. Methods The 120 health male Sprague-Dawley rats, weighing 180-220 g, were divided into 4 groups (1)STZ-modeled diabetes, fed with high-carbohydrate plus high-fat diet (n=40);(2)fed with regular diet (n=30);(3)and (4)SD rats with citrate buffer instead of STZ injection, fed with high-carbohydrate and high fat diet (n= 25);and fed with regular diet (n= 25); At the 4th, 8 th, 12 th and 16 th week after the intra-peritoneal injection of STZ solution or citrate buffer solution, rats from each group were scarified and examined. Results There were no significant differences in body mass and blood glucose among those groups after one week of feeding (P＞0. 05).After 4 weeks of feeding before injection, the body mass, fasting insulin (FINS) and insulin sensitive index (ISI) were obviously increased in diabetes group and high-carbohydrate plus high-fat control group as compared with STZ control group and normal control group (P＜ 0. 05). There were no significant differences between diabetes group and high-carbohydrate plus high-fat control group,between STZ control group and normal control group (P＞0. 05). After injection, the blood glucose,body mass, ventricular mass, TG and TC were higher in diabetes group and high-carbohydrate plus high-lipid control group than in STZ control group and normal control group (P＜0.05). The above parameters were much higher in diabetes group than in high-carbohydrate plus high-lipid control group, but there was no difference between STZ control group and normal control group (P＜0. 05).Pathological examination showed that the weight of the heart was significantly increased, the myocardial cells were hypertrophied accompanying degenerative changes and apoptosis, the interstitial collagen fibers were hyperplasia in the diabetic rats. The ultrastructures also presented severe damage.These changes indicated that cardiomyopathy was induced in the diabetes rats. Although similar changes were found in the rats fed with high-carbohydrate plus high-fat diet, they were much less significant than those in the diabetic rats. Conclusions Cardiomyopathy developes frequently in the rats with type 2 diabetes mellitus induced by feeding high-carbohydrate plus high-lipid diet and single intra-peritonial injection of 30 mg/kg STZ solution.