The effect of coxsackie virus B3 on intracellular calcium homeostasis in rat cardiomyocytes

Objective To investigate the effect of coxsackievirus B3 (CVB3) on intracellular calcium, L type voltage dependent calcium channel(VDCC) and Na +/Ca 2+ exchange (NCE) in adult rat cardiomyocytes.Methods Rat hearts were perfused with collagenase to gain single cardiomyocyte .The intracellular free calcium concentration of the cardio myocytes were detected by laser cofocal microscopy with calcium indicator, Fluo 3 acetoxymehyl ester; and the currents of VDCC, Na + and NCE were recorded by patch clamp techniques.Results The free intracellular calcium concentration increased from (51±43) nmol/L in normal cardiomyocytes to (339±208) nmol/L in CVB3 infected cardiomyocytes. The VDCC current increased from (4.13±0.75) pA/pF to (4.9±1.4) pA/pF after CVB3 infection, and the inward NEC current decreased from (-0.46±0.21)pA/pF to (-0.28±0.16)pA/pF; besides, the reverse potential of NCE was shifted from (-29.4±7.0)mV to (-41±14)mV with CVB3 infection.Conclusion The increase of L type VDCC current and decrease of inward NCE current with shift of NCE reverse potential may partly attribute to intracellular free calcium accumulation; also, it may be the cause of cell damage and the occurrence of abnormal electric activities induced by CVB3 infection.