Fig. 1. Effects of isoflurane (ISO) on norepinephrine (NE)-induced increases in force and R^340/380in either the absence (−ryanodine) or presence (+ryanodine) of ryanodine. (A ) An example of time-dependent effects of isoflurane on the norepinephrine response. The norepinephrine responses before application of isoflurane (control), 59 min after application of isoflurane, 15 min after washout of isoflurane, and 59 min after washout of isoflurane. (B ) Examples of steady-state (i.e. , maximal) effects of isoflurane on the norepinephrine response in either the absence (left ) or presence (right ) of ryanodine. (C ) Analyzed data (left , in the absence of ryanodine; right , in the presence of ryanodine) (n = 5). *P < 0.05 versus  control. **P < 0.01 versus  control.