Study of the interaction of sulfur dioxide derivative with cardiac sodium channel

摘要

The effects of sulfur dioxide (SO2) derivatives (bisulfite and sulfite, 1:3 M/M) on voltage-dependent sodium channel in isolated rat ventricular myocyte were studied using the whole cell patch-clamp technique. SO2 derivatives increased sodium current (I-Na) in a concentration-dependent manner. SO2 derivatives at 10 mu M significantly shifted steady-state inactivation curve Of I-Na to more positive potentials, but did not affect the activation curve. SO2 derivatives markedly shifted the curve of time-dependent recovery of IN. from inactivation to the left, and accelerated the recovery of I-Na. SO2 derivatives also significantly shortened the activation and inactivation time constants of I-Na. These results indicated that SO2 derivatives produced concentration-dependent stimulation of cardiac sodium channels, which due mainly to the interaction of the drug with sodium channels in the inactivated state. (c) 2005 Elsevier B.V. All rights reserved.