瞬间外向钾通道亚单位mRNA在犬左右心室中层心肌中表达的比较研究  

COMPARISON OF EXPRESSION OF ION-CHANNEL SUBUNIT mRNA IN MIDMYOCARDIUM OF CANINE RIGHT VENTRICULAR VERSUS LEFT VENTRICULAR

作　　者：陈高[1] 黄从新[1] 姚艳[1] 

机构地区：[1]武汉大学人民医院心内科,湖北武汉430060

出　　处：《实用临床医药杂志》2005年第11期49-51,57,共4页Journal of Clinical Medicine in Practice

基　　金：国家"十五"科技攻关项目;"211工程"建设项目

摘　　要：目的研究犬左右心室中层心肌瞬间外向钾电流(Ito)亚单位mRNA的表达情况,探讨左右心室复极异质性的可能分子机制。方法应用RT-PCR半定量分析犬左右心室中层心肌Ito的α亚单位(Kv4.3)、β亚单位(KchIP2)mRNA的表达量(以-βactin为内参照)。结果Kv4.3 mRNA水平在左右心室中层心肌中表达没有显著差异(P>0.05),KchIP2 mRNA水平在右室中层心肌表达明显高于左室中层心肌(P<0.01)。结论KchIP2 mRNA水平在左右心室中层心肌中表达上的差异与其相应离子流在左右心室中层心肌上的差异一致,可能是其离子流差异的分子基础。这种差异构成了心室间复极差异的基础,在尖端扭转型室性心动过速(Tdp)和多形性室性心动过速(PMVT)等室性心律失常的发生中起着重要的作用。Objective To investigate the inhomogeneity in distribution of ion channels subunit mRNA in midmyocardium of canine right ventricular（RV） versus left ventricular（LV） and the potential molecular mechanism of electrical nonuniformity in the RV versus the LV. Methods The mRNA expression and distribution of the transient outward current α-subunits Kv4.3, the β ／ ｜ subunit KchIP2 mRNA were quantified by Semiquantitative RT-PCR in tissue sections obtained from different regions of canine myocytes including RV midmyocardium, LV midmyocardium. Results Kv4.3 potassium channel α-subunit mRNA was expressed at equal levels in RV midmyocardium and LV midmyocardium（P 〉 0.05 ）, But KchIP2 mRNA was expressed much more strongly in RV midmyocardium than in LV midmyocardium （P 〈 0.01）. Conclusions The inhomogeneity in distribution of ion channels subunit mRNA in canine right RV and LV midmyocardium are consistent with, and shed light on the molecular basis of, well-recognized fundamental regional variation in midmyocardial ionic currents. This difference plays a key role in the RV versus LV electrical heterogeneity and some ventrieular arrhythmias such as torsades de pointes（Tdp）, polymorphic ventricular tachycardia（PMVT）etc.

关 键 词：犬 异质性 复极 离子流 中层心肌 MRNA 瞬间外向钾通道 室性心动过速 心律失常 

分 类 号：R331.3[医药卫生—人体生理学] R541[医药卫生—基础医学]