Fig. 5.

Excitation-contraction coupling (25 Hz/125 Hz force ratio) following lengthening contractions and effect of pharmacological modulation of ryanodine receptor (caffeine, dantrolene) in the TA muscle from mdx mice. a Ratio of 25 and 125 Hz forces following lengthening contractions in mdx mice, used as an index of excitation-contraction coupling. b Force drop following lengthening contractions in the TA muscle from mdx mice treated with caffeine or dantrolene, i.e., modulators of ryanodine receptor. c Maximal force before lengthening contractions (initial) in the TA muscle of mdx mice treated with caffeine or dantrolene. Mdx + Caf mdx mice treated with caffeine, Mdx + Dant mdx mice treated with dantrolene, a significantly different from before lengthening contractions (p < 0.05), c significant difference with non-treated mice (p < 0.05). n = 6–10 per group