| Objective To identify the existence of TRPC3current (ITRPC3) in the cardiomyocytes fromrabbit pulmonary vein muscle sleeves (PVC) and left atrial cardiomyocytes (LAC) and theregional differences of the current density between the two kinds of myocytes in order to discuss therole of TRPC3channels in the ionic mechanism of PVC.Methods The PVC and LAC were obtained by enzymatic dissociation. The whole-cellpatch-clamp technique was used to record the back-ground (IBG) current in the LAC and PVC.Pyr3, the selective and direct inhibition of TRPC3channels, was taken to identify the ITRPC3current.Results In the present work, after Pyr3perfusion, the IBGcurrent density was reduced in bothPVC and LAC, which was identified as the ITRPC3current. The ITRPC3current density of PVC wassignificantly less than LAC (–0.1225±0.0848pA/pF vs–0.3301±0.0863pA/pF;–60mV, n=10,P<0.05;0.2548±0.0898pA/pF vs0.6704±0.1247pA/pF;+60mV, n=10, P<0.05). The ITRPC3current had significantly difference (n=10, P<0.05) in them.Conclusion The existence of TRPC3channels in PVC and LAC has been identified, and theITRPC3current density of PVC is significantly lower than LAC. It is suggested that the TRPC3channels might play an important part in the genesis of early after depolarization (EAD) originatedfrom the pulmonary vein sleeves. |
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