Fig. 9. Effects of isoflurane on Ca2+-force relation in the β-escin membrane-permeabilized strips. (A ) An example of the effect of 5% isoflurane on the Ca2+-force relation. Note that isoflurane influences the Ca2+-force relation very little. (B ) Analyzed data. The Ca2+-force relation was assessed after the normalization of the Ca2+-activated contraction to 100%. The EC50values for the Ca2+-force relations before (control) and after exposure to isoflurane were 1.9 and 2.4 μm, respectively. n = 4.