Fig. 7. Effects of bupivacaine on ion currents under action potential voltage clamp conditions. Representative records of a command signal (  A ) and the underlying current traces obtained in the presence of increasing concentrations of bupivacaine (  B ). (  C ) Suppressive effects of ropivacaine on the inward and late outward current peaks.  Symbols and  bars represent mean ± SEM values obtained in four myocytes. * Significant (  P < 0.05) change from control.