Fig. 2. (A ) Mean force transients induced by 10 mm caffeine after loading in the presence of 1, 5, 10, and 15 mm bupivacaine. *P < 0.05 compared with transient induced after loading in the absence of bupivacaine. (B ) Conversion of force transients (A ) into corresponding [Ca2+] transients, based on individual [Ca2+]-force relation of each fiber. *P < 0.05 in comparison to control [Ca2+] transients after loading in the absence of bupivacaine. (C ) Remaining force transients assessed in the presence of 1, 5, 10, and 15 mm bupivacaine 60 s after the initial caffeine induced force peak and normalized to the latter. *P < 0.05 compared with remaining caffeine-induced transients in the absence of bupivacaine. (D ) Conversion of force transients (C ) into corresponding [Ca2+] transients. *P < 0.05 compared with remaining [Ca2+] transients in the absence of bupivacaine.