左心室肥厚兔缓慢型延迟整流钾电流通道KCNQ1和KCNE1 mRNA表达的变化

摘要

目的:观察左心室肥厚兔左心室内外膜心肌细胞中缓慢型延迟整流钾电流(IKs)通道KCNQ1和KCNE1 mRNA表达水平的差异,探讨IKs通道在兔肥厚心肌复极离散度增大中的作用.方法:55只雄性日本大耳白兔随机分为实验组30只和对照组25只.实验组行肾上腹主动脉次全结扎,使腹主动脉缩窄50%~60%;对照组除不做丝线结扎外,其余处理同实验组.术后8周处死动物,应用荧光定量PCR技术检测IKs通道KCNQ1和KCNE1 mRNA的表达.结果:对照组左心室内膜IKs通道mRNA表达水平低于心外膜(P<0.001);实验组左心室内外膜IKs通道mRNA表达水平均低于对照组(P<0.001).结论:IKs通道减少使复极时限延长,其不均一性减小可能是肥厚心肌复极离散度增大的原因.%Aim:To reveal the regional heterogeneity of KCNQ 1 and KCNE1 expression at the mRNA level in left ven-tricular epicardium and endocardium , and explore the effect of slowly activating delayed rectifier potassium ( IKs ) on the amplified transmural dispersion of repolarization in hypertrophied left ventricular epicardium and endocardium of rabbits . Methods:A total of 55 male Japanese rabbits were included and randomly assigned to experimental group ( n=30 ) and control group(n=25).In the experimental group, abdominal artery of rabbits was subjected to 50%-60% reduction by partial ligation for 8 weeks to produce left ventricular hypertrophy ( LVH) .Real-time quantitative reverse transcription PCR was performed to detect levels of expression of KCNQ 1 and KCNE1 mRNA.Results:In the control group , left epicardium (L-Epi) had higher expression levels of IKs than left endocardium (L-Endo)(P<0.001).Compared with control group, the expression of IKs in the expreimental group was significantly decreased in L-Endo and L-Epi(P<0.001).Conclu-sion:The decrease of IKs could prolong ventricular repolarization duration , the decreased heterogeneity of IKs may be the reason of amplified transmural dispersion of repolarization in hypertrophied myocardium .