Contribution of Nav1.1 to cellular synchronization and automaticity in spontaneous beating cultured neonatal rat ventricular cells

Abstract

Two factors of cell coupling influence cellular synchronization and automaticity: gap junction coupling and ion channels activity. However, the role of Na+ channel isoforms underlying cell-to-cell interaction and cellular automaticity is not well understood. To address these questions, we studied mRNA expression of Na+ channel isoforms and the effects of TTX on spontaneously beating cultured ventricle cells. Using RT-PCR technique we demonstrated the presence of Nav1.1 and Nav1.5 channels. The reduction of Nav1.1 channel activity disturbed cell-to-cell interaction and changed beating rates. Thus, Nav1.1 channel is involved in cellular synchronization and automaticity.