Figure 4

S107 treatment increases muscle force and exercise capacity in β-sarcoglycan deficient mice. (A) Force-frequency curves of EDL muscle from WT control, β-sarcoglycan-deficient (Sgcb−/−), and S107-treated Sgcb−/− (Sgcb−/− S107) mice. (B) Fatigue stimulation (50 tetani; each tetanic stimulation had a duration of 350 ms and was produced by stimulating the muscle with 0.5 ms pulses at 70 Hz frequency) on the same muscles as (A). (C) Relative decline in force production during fatigue in (B). EDL force measurements are presented as mean ± SEM, n = 6–9. (D, E) Exercise capacity in Sgcb−/− mice is improved by S107. Daily voluntary running distance (D) and average running speed (E). Pooled data are presented as mean ± SEM, n = 8–5, * P <0.05 (ANOVA).