Abstract: Objective: To study the method of acute isolating rabbit left atrial myocytes and analysis the electrophysiological characters. Methods: Left atrial myocytes of 10 rabbits were isolated by perfusion of coronary artery and enzymatic dissociation. Whole-cell patch-clamp technique was used to record action potential (AP) and ionic channel currents (ICaL and INa). Results: Single rabbit left atrial myocyte with normal morphology was obtained．AP and the membrane currents of ICaL and INa were successfully recorded．The resting potential averaged respectively -62.8±2.4mV. APD90 and APD50 decreased as stimulation frequency increased. APD90 and APD50 of 4Hz or 5Hz were significant differences compared with 1Hz of stimulation frequency (P<0.05). The densities of ICaL were -4.79±1.28pA/pF, activited potential was -40mV, potential of peak current was +10mV, reversed potential was +40～+50mV. The densities of INa were -118.41±16.67pA/pF, activited potential was -60mV, potential of peak current was -40mV, reversed potential was +20～+30mV. Conclusion: These results suggest that, left atrial myocytes of dissociating model own normal electrophysiological activity and features, which can be used to study atrial electrical and ionic channel remodeling of atrial fibrillation．

Key words: atrial myocytes, action potential, L-calcium channel, sodium channel