甲状腺素对大鼠心肌T型钙通道蛋白和mRNA的影响  

Effects of thyroid hormone on myocardial T-type calcium channels at mRNA and protein levels in rats

作　　者：傅润熹 杨若松[1] 黄雪琴 何文明 余莜燕 韦登明[1] FU Run-xi;YANG Ruo-song;HUANG Xue-qin;HE Wen-ruing;YU You-yah;WEI Deng-ming(Department of Pathology,Medicine School of Ningbo University,Ningbo 315211,China)

机构地区：[1]宁波大学医学院病理学系,浙江宁波315211

出　　处：《中国病理生理杂志》2018年第6期996-1001,共6页Chinese Journal of Pathophysiology

基　　金：浙江省自然科学基金资助项目(No.LY16H230001);宁波市自然科学基金资助项目(No.2017A610206)

摘　　要：目的:观察甲状腺素对大鼠心肌T型钙通道Cav3.1、Cav3.2和Cav3.3表达的影响,探讨T型钙通道表达变化与甲亢性心脏病引起的心律失常之间的关系。方法:选取健康SD大鼠20只,随机分为正常对照组和甲亢性心脏病组(n=10),腹腔注射L-甲状腺素(0.5 mg/kg)连续35 d建立大鼠甲亢性心脏病模型。检测各组大鼠血清T3和T4的含量,测定各组大鼠心脏指数和心肌细胞横径,并行心电图检查;免疫组化和Western blot检测各组大鼠心肌T型钙通道蛋白的表达;RT-PCR检测心肌T型钙通道mRNA的表达。结果:造模35 d后与正常对照组比较,甲亢性心脏病组大鼠血清T3和T4含量明显升高,心脏指数和心肌细胞横径明显增加(P<0.05),并发生心律失常;免疫组化、Western blot和RT-PCR结果显示,甲亢性心脏病组大鼠心肌Cav3.1表达较正常对照组明显增加(P<0.05),Cav3.2表达明显减少(P<0.01),Cav3.3的表达无变化。结论:甲状腺素可促进心肌Cav3.1mRNA和蛋白的表达,抑制Cav3.2 mRNA和蛋白的表达,而对Cav3.3的表达则没有影响。Cav3.1和Cav3.2的表达变化可能与甲亢性心脏病心律失常的发生有关。AIM： To observe the effect of thyroxine on the expression of T-type calcium channels Cav3. 1,Cav3. 2 and Cav3. 3 in rat myocardium,and to explore the possible biological mechanism between the changes of the expression of T-type calcium channels and the arrhythmia in hyperthyroid heart disease. METHODS： Healthy SD rats（ n =20） were randomly divided into normal control group（ n = 10） and hyperthyroid heart disease group（ n = 10）. The animal model was established by intraperitoneal injection of levothyroxine for 35 d. The contents of T3 and T4 in serum,the heartto-body weight ratio,the diameter of cardiac myocytes and electrocardiograph were measured to evaluate hyperthyroid heart disease. Moreover,the mRNA and protein expression levels of T-type calcium channels in the myocardium were measured by RT-PCR,immunohistochemistry and Western blot. RESULTS： After intraperitoneal injection of levothyroxine for 35 d,compared with the normal control group,the serum contents of T3 and T4,the heart-to-body weight ratio and the diameter of cardiac myocytes were significantly increased in hyperthyroid heart disease group（ P〈0. 05）,and arrhythmia occurred in hyperthyroid heart disease group. By immunohistochemistry and Western blot,the protein expression of Cav3. 1 increased significantly（ P〈0. 05）,while the protein expression of Cav3. 2 decreased significantly（ P〈0. 01）. However,no change of the Cav3. 3 protein was observed. The results of RT-PCR were the same as immunohistochemistry and Western blot. CONCLUSION： Thyroxine promotes the expression of Cav3. 1 in the myocardium but inhibits the expression of Cav3. 2 at mRNA and protein levels,which might be involved in arrhythmia in hyperthyroid heart disease.

关 键 词：甲状腺素 甲状腺功能亢进性心脏病 T型钙通道 心律失常 

分 类 号：R581.1[医药卫生—内分泌] R363[医药卫生—内科学]