中文摘要：

目的：利用原代培养的心房肌细胞建立快速起搏模型，对心房颤动（房颤）早期的重构现象进行初步研究。方法：原代培养大鼠心房肌细胞，并建立快速电场刺激起搏细胞模型，利用全细胞膜片钳技术记录刺激前后心房肌细胞的动作电位周期，透射电镜观察细胞超微结构的变化。结果：培养至第4天，细胞生长密度可以达到瓶底70％左右，数目可达（2～3）×10^9／L，经免疫细胞化学鉴定，90％以上培养细胞α-肌动蛋白抗体染色阳性；全细胞膜片钳记录了培养心房肌细胞及经电场刺激（600次／min，1．5V／cm）24h后的心房肌细胞的动作电位周期，动作电位周期分别为（64．2±4．6）ms和（56．6±4．1）ms，刺激前后差异有统计学意义（P〈0．05）。透射电镜观察到刺激后心房肌细胞超微结构发生去分化改变。结论：经快速起搏24h后，心房肌细胞发生了电及结构重构；利用原代培养的心房肌细胞建立快速起搏的房颤模型，可以对房颤早期的重构机制进行研究。

英文摘要：

Objective：To explore early electrical and structural remodeling in atrial fibrillation utilizing a rapid paced primary cultured atrial myocyte model. Method： Primary rat atrial myocytes were cultured and established as a rapid paced primary cultured atrial myocyte model. Atrial cells were cultured in the presence of rapid field stimulation （600 beats per min, 1.5 V/cm） for 24 h. Action potential duration were recorded from stimulated cells and control cells using whole-cell voltage-clamp techniques. Ultrastructure of myocardial cells were observed under electron microscope. Result .. After 4 days of primary culture, the number of cells reached （2-3） ）〈 10^6 per milliliter. Immunocytochemical analysis showed that over 90 percent of cells were stained positively forα-actin, a factor specific for cardiomyocytes. The action potential duration was shortened through the rapid pacing compared with those before pacing （ P 〈0.05）. Results of electron microscope showed that atrial myocytes generated dedifferentiation through pacing. Conclusion：Rapid stimulation of atrial cells in culture produces electrical remodeling, recapitulating principal phenotypic features of atrial tachycardia remodeling in vivo. It is available that a rapid paced cell model is established with primary cultured atrial myocyte to study the mechanism of early electrical and structural remodeling for atrial fibrillation.