Spatio-temporal analysis of intracellularcalcium oscillation in the pulmonary vein myocardium

本研究测定了肺静脉心肌的电生理特性，并分析了其致心律失常活性。一些肺静脉心肌细胞，但不是心房心肌细胞，表现出持续的自发性Ca2+瞬变。但肺静脉心肌细胞的形态和肌浆网含量与心房肌细胞相同。肺静脉心肌细胞静息膜电位负性和内向整流钾电流密度均低于心房肌。这些结果表明，在肺静脉心肌细胞的较低密度的复极化电流似乎起着允许的作用，由细胞内Ca 2+的升高引起的去极化。

We assessed the electrophysiological properties of pulmonary vein myocardium and analyzed its arrhythmogenic activity. Some of the pulmonary vein cardiomyocytes, but not atrial cardiomyocytes, showed sustained spontaneous Ca2+transients. But morphology and the sarcoplasmic reticulum content of pulmonary vein cardiomyocytes were the same as those of atrial myocytes. The pulmonary vein myocardium had a less negative resting membrane potential and lower density of inwardly rectifying potassium current than atrial. These results suggest that the lower density of repolarizing currents in pulmonary vein cardiomyocytes appears to play a permissive role for depolarization induced by elevation of intracellular Ca2+.