心房颤动患者乙酰胆碱依赖性钾通道和快速延迟整流钾通道基因表达的研究

Alteration in gene expression of the acetylcholine dependent potassium channel and rapid delayed rectifier potassium channel in patient with atrial fibrillation

目的研究心房颤动(AF)患者心房组织中乙酰胆碱依赖性钾通道(Kach)和快速延迟整流钾通道(Kr)的基因表达。探讨AF时心房组织Kach和Kr的mRNA表达改变及其意义。方法自20例因风湿性心脏病或先天性心脏病接受外科手术的患者,于术中采取的右心耳标本分为2组,窦性心律(SR)组14例,慢性AF组6例,应用半定量逆转录聚合酶链反应(RTPCR)技术,检测心房组织Kach和Kr基因表达。结果心房组织中Kir34(Kach的一种成分)和KrmRNA的表达,与SR组051±005相比AF组029±005下调43%,差异有显著性(P<0001),而KrmRNA水平在SR组056±003和AF组057±003之间无明显改变,差异无显著性(P>005)。结论房颤患者KachmRNA表达下调,可能是心房肌细胞IKach密度减弱的分子基础。Kr转录水平无明显改变。

Objective The purpose of this study is to investigate alterations in gene expression of the acetylcholine dependent potassium channel and rapid delayed rectifier potassium channel in patient with atrial fibrillation (AF). Methods Right atrial appendages specimen were obtained from 6 patients with chronic AF(AF group) and 14 matched controls in sinus rhythm (SR group) while these patients undentwent open heart surgery. Total RNA was isolated and reversely transcribed into cDNA. In a semi quantitative polymerase chain reaction the cDNA of interest and of glyceraldehydes 3 phosphate dehydrogenase were coamplified and separated by ethidium bromide stained gel electrophoresis. Result The content of Kir 3 4 mRNA in AF group (0 29±0 05) was significantly lower than that in SR group (0 51±0 05), P <0 001. There was no significant difference in the gene expression of Kr between SR group (0 56±0 03) and AF group (0 57±0 03), P >0 05. Conclusion These data suggest that transcriptional down regulation of Kach may serve as the molecular basis of I Karh remodeling in patient with chronic AF. The mRNA level of Kr is unchanged in choric AF patients.