Objective To study the effect of
ropivacaine on ion channels in isolated ventricular myocytes Methods Single ventricular
cell of guinea pig was obtained by an enzymatic dissociation method The whole cell configuration of the patch clamp recording technique was used to record the changes of sodium current(INa),L type calcium current(ICa L), delayed
rectifying K + current(IK) and inward rectifying K + current(IK 1) following the administration of
ropivacaine at 50μmol L 1 and 100μmol L 1 Results Ropivacaine reduced the amplitude of INa and ICa L in a dose dependent manner INa and ICa L were decreased by 36 8% and 7 86% respectively after administration of 50μmol L 1 ripovacaine Ropivacaine 100μmol L 1 decreased the amplitude of INa and ICa L by 66 1% and 23 13% Ropivacaine 100μmol L 1 did not change the amplitudeof IK and IK 1 (P>0 05) Conclusion The cardiotoxicity of ropivacaine is related to the inhibition of sodium and calcium channels