Figure 2. Effects of isoflurane (2.5 vol%) and sevoflurane (2.5 vol%) on inactivation of peak amplitude of Calcium2+ current (ICa). (A) Representative recordings of ICain the absence (open symbols) and presence (closed symbols) of isoflurane. ICawas elicited in response to a depolarization pulse of +20 mV from a holding potential of -40 mV. (B) Time courses of inactivation (indicated by a dashed square in A) of I sub Ca plotted in semilogarithmic charts in the absence (open circles) and presence (closed circles) of isoflurane (2.5 vol%). The continuous lines were the best fit of time constant values to equation 1. The decay of the current is well fitted by a single exponential time course. (C) The effects of sevoflurane (2.5 vol%) on the decay of ICa. Open squares = control; closed squares = sevoflurane.