Longer-term treatment with THI elevated muscle force in uninjured mdx EDL muscles. ( A ) Experimental schematic outlining the treatment regimen. Beginning at 4 weeks of age, mdx4cv mice (1-MO males) were treated for 4 weeks ad libitum with 50 mg/l THI (n = 4) or vehicle (n = 3) in drinking water. ( B ) Myography analysis of EDL muscles reveals a significant increase in maximal specific force with THI treatment. *P <0.05 by student’s t-test. Error bars represent SEM. ( C ) Summary of findings: S1P can act to not only promote myogenic cell activation and muscle repair, but also enhance muscle fiber size and force, possibly through S1PR1 mediated signaling. EDL, extensor digitorum longus; MO, month-old; S1P, sphingosine-1-phoshate; S1PR1, S1P receptor 1; SEM, standard error of the mean; THI, 2-acetyl-4(5)-tetrahydroxybutyl imidazole.