大鼠胚胎期心脏Na^+通道基因SCN5A的表达  

Expression of sodium channel gene SCN5A in the heart during rat embryogenesis

作　　者：金剑峰[1] 董钦[1] 李凤兰[1] 陈诗慧[1] 马宁[1] 李晖[1] 

机构地区：[1]哈尔滨医科大学基础医学学院生物化学与分子生物学教研室,黑龙江哈尔滨150081

出　　处：《哈尔滨医科大学学报》2006年第4期286-289,共4页Journal of Harbin Medical University

摘　　要：目的研究大鼠胚胎发育过程中,编码心肌组织电压门控Na+通道α亚单位SCN5A基因mRNA的表达和蛋白定位。方法大鼠胚胎期分7个时间点(E12.5-P1),提取心脏总RNA,RT-PCR和免疫组化方法分别检测SCN5A基因mRNA表达和蛋白定位。结果大鼠胚胎发育期SCN5A基因mRNA表达呈动态模式,E12.5d(0.425±0.012)表达最少,E13.5d(0.532±0.012)和E14.5d(0.665±0.119)相对增加,E15.5d达到高峰(1.08±0.01),E17.5d(0.870±0.035)与E19.5d(0.855±0.057)相比略有降低,无显著性差别,提示胚胎发育后期表达量趋于平衡。出生后一天(P1)表达量(0.751±0.041)较胚胎期表达显著降低。除E17.5d与E19.5d比较无统计学意义外(P>0.05),其余组间比较均有统计学意义(P<0.001)。免疫组化结果显示,SCN5A蛋白表达高峰及在左、右心室肌及室间隔中表达持续时间各不相同,胚胎早期SCN5A蛋白在不同心腔表达相对均匀,后期在心外膜和心室左、右束支位置表达增强。结论SCN5A基因与大鼠胚胎心脏传导系统发生及其功能相关,Na+电流是形成胚胎发育中期心肌动作电位的主要成分。Objective The aim of this study is to analyze SCN5A mRNA expression levels and protein distribution of SCN5A during rat cardiac development. Methods SCN5A mRNA levels were determined by RT- PCR using embryonic hearts ranging from E12.5 to E19.5 as well as in postnatal 1 day （Seven time points）. SCN5A protein distribution and localization during cardiogenesis were analyzed by immunohistochemistry and microscopy. Results SCN5A mRNA expressed lowest in amount on El2.5 （0.425 ± 0.012）, E13.5 （0.532 ± 0.012） and E14.5（0.665 ± 0.119） slightly increase,while highest on E15.5 （ 1.08 ± 0.01 ） with significant difference. Then decreased on El7.5 （0. 870 ± 0. 035 ） and El9.5 （0. 855 ± 0. 057 ） （ P 〉 0.05 ） and showed stable expression during this late stage of embryogenesis. The expression on P1 （0. 751 ± 0. 004）was even lower than late stage. The other group comparison had statistic significance （ P 〈 0. 001 ） except group between El7.5 and E19.5. Immunohistochemistry result showed that, SCN5A protein was homogeneous in all heart chambers in the early embryo stage, whereas in the late stage, high level of SCN5A protein is accumulated in epicardium and bundles area. Conclusion SCN5A gene has some relevance with formation and function of cardiac conduction system during rat embryogenesis, and sodium current contribute to the main components in action potential of myocardium at rat middle embryogenesis.

关 键 词：心肌 胚胎 SCN5A 基因表达 

分 类 号：R331.3[医药卫生—人体生理学] R-332[医药卫生—基础医学]