Fig. 4. The effect of increasing isoflurane concentration on the relation between intracellular [Ca²⁺] and force redevelopment. Tension redevelopment (k^TR) was normalized to the value obtained in 12 mm extracellular [Ca²⁺]. pCa =−log[Ca²⁺]. n = 8 for each concentration, except n= 7 for 1.5 MAC. * P < 0.05 for mean slope of fitted lines in the presence of isoflurane compared with control conditions.