Fig. 1. Concentration–response experiment for isoflurane. (Top ) Aequorin luminescence and force traces as functions of time during a cumulative concentration–effect experiment on isoflurane in isometric twitches. Sixty-four twitches were averaged. (Bottom ) Aequorin luminescence, shortening, force, and velocity of shortening traces as functions of time during a cumulative concentration–response experiment on isoflurane in isotonic twitches at L^max. Sixteen twitches were averaged. The small vertical arrow near the origin of the aequorin signal indicates the time of the stimulus. Top and bottom panels are records from different muscles.