钙敏感受体对大鼠糖尿病性心肌病的影响

Decreased expression of calcium-sensing receptor involved in the progression of diabetic cardiomyopathy

目的:观察钙敏感受体(Ca SR)在大鼠糖尿病性心肌病中的作用。方法:30只雄性Wistar大鼠随机分为对照组、糖尿病4周组和糖尿病8周组(n=10)。高糖高脂饮食4周后腹腔注射STZ(30 mg/kg)建立糖尿病模型。通过透射电镜观察心肌超微结构的变化,通过Western blot检测心肌组织Ca SR、肌浆网Ca2+-ATPase(SERCA)和受磷蛋白(PLN)的蛋白表达。结果:与对照组相比,随着病程的延长糖尿病组大鼠心肌Ca SR、SERCA蛋白表达降低,PLN表达增加,心肌结构损伤逐渐加重。结论:在大鼠糖尿病性心肌病进展过程中Ca SR的表达逐渐降低,并可能导致钙稳态紊乱参与糖尿病心肌病的发生。

Objective： To observe the dynamic expression of calcium-sensing receptor（ Ca SR） in myocardium of diabetic rats.Methods： Thirty male Wistar rats were randomly divided into 3 groups including control,diabetic-4 week and diabetic-8 week groups（ n = 10）. The type 2 diabetes mellitus models were established by intraperitoneal injection of streptozotocin（ STZ,30 mg/kg） after high-fat and high-sugar diet for one month. The cardiac morphology was observed by electron microscope. Western blot analyzed the expression of Ca SR,phospholamban（ PLN）,a calcium handling regulator,and Ca2 ＋-ATPase（ SERCA） in cardiac tissues. Results：Compared with control group,the expressions of Ca SR and SERCA were decreased,while the expression of PLN was significantly increased in a time-dependent manner in diabetic groups. Meanwhile diabetic rats displayed abnormal cardiac structure. Conclusion：These results indicate that the Ca SR expression of myocardium is reduced in the progression of DCM,and its potential mechanism may be related to the impaired intracellular calcium homeostasis.