白藜芦醇对糖尿病大鼠心功能障碍及酸性鞘磷脂酶-神经酰胺通路的影响

Effects of resveratrol on cardiac dysfunction and ASMase-ceramide pathway in type 2 diabetic rats

目的:观察白藜芦醇(RSV)对糖尿病大鼠心功能障碍的影响并探讨其与酸性鞘磷脂酶-神经酰胺通路的关系。方法:通过一次性腹腔注射小剂量链脲佐菌素(STZ;30 mg/kg)联合高脂饮食饲养12周构建2型糖尿病(T2DM)大鼠模型。实验分为正常对照(control)组、T2DM组、T2DM+RSV组(灌胃给予糖尿病大鼠白藜芦醇100 mg·kg^(-1)·d^(-1))和RSV组(正常大鼠灌胃给予同等容量RSV),共灌胃12周,每周称量体重并调整给药剂量。实验结束后,釆用小动物M型超声检测模型大鼠心脏功能、形态和结构的变化;颈动脉插管检测血流动力学变化;生化方法检测血清中糖、脂水平以及心脏组织中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量;油红O染色和天狼星红染色分别观察心脏组织中脂肪堆积和心肌纤维化情况;高效液相质谱法检测心脏组织中神经酰胺(ceramide)含量;Western blot检测酸性鞘磷脂酶(ASMase)和过氧化物酶增殖体激活受体γ辅激活因子1α(PGC^(-1)α)的蛋白表达。结果:T2DM组大鼠空腹血糖、甘油三酯、胆固醇及低密度脂蛋白胆固醇水平均较control组显著升高,心功能显著降低(P<0.05);T2DM组大鼠心脏组织中脂肪堆积、MDA含量显著增加(P<0.05),SOD活性、ATP水平和PGC^(-1)α蛋白表达均显著降低(P<0.05),且出现明显心肌纤维化;给予白藜芦醇治疗12周可显著改善以上指标的异常变化,同时,显著下调糖尿病大鼠升高的心肌ASMase蛋白和ceramide水平。结论:白藜芦醇可显著改善糖尿病诱导的大鼠心功能障碍和心肌纤维化,其机制可能与抑制ASMase-ceramide通路有关。

AIM： To investigate the effects of resveratrol（ RSV） on cardiac dysfunction and acid sphingomyelinase（ ASMase）-ceramide pathway in diabetic rats. METHODS： Type 2 diabetes mellitus（ T2 DM） model was established by a high-fat diet combined with STZ intraperitoneac injection（ 30 mg/kg）. SD rats（ n = 20） were randomly divided into control group,T2 DM group; T2 DM ＋ RSV group（ diabetic rats were given resveratrol at 100 mg·kg·d-1 by intragastric administration for the treatment） and RSV group（ some of control rats were selected to give the same dose of RSV for drug control group）. The M-mode Doppler ultrasonography was performed to observe the changes of cardiac function and structure in the rats. The levels of serum glucose,lipid and superoxide dismutase（ SOD） activity,malondialdehyde（ MDA） content in heart tissues were measured. Oil red O staining and Sirius red staining were performed to observe lipid accumulation and cardiac fibrosis in heart tissues. The cardiac ceramide concentration in diabetic rats was analyzed by high-performance liquid chromatography. The protein expression of ASMase and peroxisome proliferator-activated receptor-γco-activator 1α（ PGC-1α） in the hearts was determined by Western blot. RESULTS： Compared with the control group,the levels of fasting blood glucose,total cholesterol（ TC）,triglyceride（ TG） and low-density lipoprotein cholesterol（ LDLC） were significantly elevated in T2 DM group. The values of ± dp/dtmax,fractional shortening and ejection fraction were declined,and the left ventricle internal dimension at end-systole（ LVIDs） and left ventricle internal at end-diastole（ LVIDd） were increased. Furthermore,increased MDA content and more lipid accumulation were also observed in diabetic hearts,while the SOD activity,ATP content and PGC-1α expression were reduced in diabetic hearts. However,all these parameters were reversed by addition of RSV,concomitant with decreased ASMase expression and ceramide content. CONCLUSION： RSV dramatically alleviates diabetes-induced cardiac dysfunction and cardiac fibrosis,which may attribute to inhibition of ASMase-ceramide activation.