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目的 研究2型糖尿病大鼠心房组织钙离子通道的表达及钙电流的改变情况.方法 30只雄性Wistar成年大鼠随机分为对照组和糖尿病组.其中糖尿病组高脂高糖饮食4周后给予小剂量链脲佐菌素35 mg/kg腹腔注射,建立2型糖尿病模型.8周后取两组大鼠的血清测定血糖、胰岛素、总胆固醇、甘油三酯、低密度脂蛋白以及高密度脂蛋白,判定两组的代谢情况.将固定后的大鼠心房组织切成冰冻切片,通过免疫荧光双标染色法测定两组的Cav1.2,Cav3.1和Cav3.2的表达情况.采用Langendorff装置进行急性分离成年大鼠心房细胞,通过全细胞膜片钳技术分别测定两组L型和T型钙电流的峰值电流、I-V曲线、稳态激活和失活电流曲线等数据.结果 与对照组相比,糖尿病组有严重的代谢紊乱,Cav1.2的蛋白表达降低,Cav3.1的蛋白表达升高,Cav3.2的蛋白表达未见明显改变.另外,糖尿病组L型钙电流的峰值电流显著降低(P＜o.05)、电流-电压(I-V)曲线下移、稳态激活和失活电流曲线未见明显差异(P＞0.05),T型钙电流的峰值电流显著升高(P＜0.05)、电流-电压(I-V)曲线上移、稳态激活电流曲线未见明显差异(P＞0.05).结论 2型糖尿病大鼠心房肌细胞有着明显的钙通道重构,导致L型钙电流密度下降,T型钙电流密度上升.“,”Objective To explore the atrial calcium channel expression and changes of calcium current in streptozotocin(STZ) induced type 2 diabetic rats.Methods We randomly divided Wistar rats into two groups:control group and diabetic group.After four weeks of a high-fat and high-sucrose diet,type 2 diabetes was induced in rats by a single dose injection of STZ(35 mg/kg).Eight weeks after injecting STZ,rats were assessed by metabolic tests,such as plasma glucose,insulin,total cholesterol,triglyceride levels,low-density lipoproteins,and high-density lipoproteins.After fixed,the rat atrial tisgues were made to frozen sections.The distribution and expression of Cav1.2,Cav3.1,and Cav3.2 in type 2 diabetes atrial tissue were detected by co-immunofluorescence.Inward calcium currents (Ica-L and ICa-T) were recorded in atrial myocytes,isolated by the Langendorff devices,using whole-cell patch clamp techniques.Results Compared to control group,diabetic group displayed severe metabolic disorders.The expression of Cavl.2 was significantly decreased,while that of Cav3.1 was significantly increased in diabetic rats.Diabetic atrial myocytes showed significantly reduced L-type Ca2+ currents,down-moved I-V curve,and increased T-type Ca2+ currents,up-moved I-V curve,but their voltage-dependent activation and inactivation curves were unchanged.Conclusion Calcium channel remodeling exists in the atrium of type 2 diabetic rat,resulting L-type Ca2+ currents decreasing and T-type Ca2+ currents increasing.