有氧运动和膳食控制对2型糖尿病大鼠心肌细胞凋亡的影响

The Effect of Exercise and Dietary Control on Cardiomyocyte Apoptosis in Type 2 Diabetic Rats

目的:探讨有氧运动联合膳食控制对2型糖尿病大鼠心肌细胞凋亡的影响及其机制。方法:选用6周龄雄性SD大鼠62只,随机抽取8只大鼠作为正常对照组(C组),喂以标准饲料;其余54只在喂饲高脂高糖膳食的基础上,腹腔注射小剂量链脲佐菌素(STZ),建立2型糖尿病动物模型。然后将2型糖尿病大鼠随机分成4组:DM对照组(DM组,n=9)、DM+运动锻炼组(DME组,n=10)、DM+膳食控制组(DMD组,n=10)和DM+运动锻炼+膳食控制组(DMED组,n=10)。DM组大鼠继续喂饲高脂高糖饲料,不进行运动锻炼;运动锻炼采用每天60 min、每周6天的无负重游泳运动;膳食控制采用与DM组等量的标准饲料。12周后,检测各组大鼠空腹血糖(FPG)水平、心肌细胞凋亡指数、心肌组织Bcl-2和Fas含量。结果:①DM组心肌细胞凋亡指数和Fas含量显著高于C组(P<0.01),Bcl-2含量显著低于C组(P<0.05)。②通过双因素方差分析,有氧运动或膳食控制可以显著降低糖尿病大鼠心肌细胞凋亡指数和Fas含量(P<0.01),升高Bcl-2含量但无统计学意义(P>0.05),而有氧运动联合膳食控制对降低糖尿病大鼠心肌细胞凋亡指数和Fas含量、升高心肌组织bcl-2含量具有显著的交互作用(P<0.01)。结论:①糖尿病大鼠心肌细胞凋亡增加,而心肌组织Bcl-2含量降低和Fas含量升高可能是心肌细胞凋亡增加的重要机制。②长期有氧运动或膳食控制可以显著降低糖尿病大鼠心肌细胞凋亡,且有氧运动联合膳食控制对减少糖尿病大鼠心肌细胞凋亡具有显著交互作用。同时,升高心肌组织Bcl-2含量、降低心肌组织Fas含量可能是长期有氧运动联合膳食控制减少心肌细胞凋亡发生的重要机制。

Objective To explore the effect of aerobic exercise and dietary control on the cardiomy- ocyte apoptosis in type 2 diabetic rats. Methods 8 of 62 6-week-old male SD rats were randomly select-ed as normal control group （C ,fed with standard diet）. The remaining 54 SD rats were used to establish animal models of type 2 diabetes （DM） through intraperitoneal injection of low-dose streptozotocin and feeding high-fat and high-carbohydrate diet. Then they were randomly divided into 4 groups：DM control group（DM,n = 9）,DM＋ aerobic exercise group（DME,n = 10）,DM＋ diet control group（DMD,n = 10）, DM＋ aerobic exercise ＋ diet control group（DMED,n = 10）. The rats in group DM were continuously fed with high-fat and high-carbohydrate diet without exercise. 60 min unloaded swimming 6 times per week was used as aerobic exercise. Rats in diet control groups were fed with the standard diet. 12 weeks later,fasting plasma glucose （FPG）, cardiomyocyte apoptosis index, Bcl-2 and Fas content were examined. Re-suits ①As compared with group C ,cardiomyocyte apoptosis index and Fas content increased, and Bcl-2 content decreased significantly （P 〈 0.01 and P 〈 0.05,respectively） in group DM; ② cardiomyocyte apoptosis index and Fas content in groups DMED decreased significantly （P 〈 0.01 ） ,while there was a significant interaction on decreasing cardiomyocyte apoptosis index and Fas content, and increasing Bcl-2 content in group DMED（P 〈 0.01 ）. Conclusion ①Increased cardiomyocyte apoptosis index in diabetic rats probably caused by the decreased Bcl-2 content or increased Fas content. ercise or dietary control, especially the combination of them could significantly apoptosis in diabetic rats. ②Long term aerobic ex-reduce the cardiomyocyte.