Fig. 3. S (−)-ropivacaine (83 μm) shifted the midpoint of current activation to more depolarized potentials and increased the slope factor of the activation curve ( A and table 2,). S (−)-ropivacaine (83 μm) did not alter the steady state inactivation of Kv4.3/KChIP2.2 channels ( B and table 2,) but altered recovery from inactivation ( C ). Whereas under control conditions recovery from inactivation occurred by a monoexponential process, S (−)-ropivacaine (83 μm) slowed recovery from inactivation by inducing a second time constant ( C and table 2 ). Inhibition of Q increased with increasing membrane potentials ( D ; P < 0.05, n = 6). The decrease of time constant of fast initial current decline under control as well as under drug condition was significant ( E ; P < 0.05, n = 6). It was adequately described by monoexponential functions (y = 16 * e−0.04x, r = 0.98, and y = 34 * e−0.007x, r = 0.98, respectively). The difference between the time constants increased with increasing membrane depolarizations. The linear voltage dependence of the size of the amplitudes of inactivation time constants ( F , n = 6) under control and washout conditions (slope = 1.15, r = 1.0) was removed by the local anesthetic (slope = 0.02, r = 0.28). Shown are mean values ± SD.