Fig. 5.

Assessment of maximum isometric tetanic force properties of the EDL muscle. The absolute isometric tetanic force, specific isometric tetanic force, time to maximum force, and half relaxation time of the EDL muscle were compared between BL10, mdx, and all 3 transgenic mdx mice at 6 (A) and 20 (B) mo of age. Time to peak tension and half relaxation time are determined from maximal tetanic stimulation. *mdx mice are significantly different from age-matched BL10 mice. †mdx mice are significantly different from all other age-matched mice strains. ‡ΔR2-15/ΔR18-23/ΔC transgenic mice are significantly different from age-matched mdx, ΔR4-23/ΔC, and ΔH2-R15 transgenic mdx mice. #ΔH2-R15 transgenic mdx mice are significantly different from age-matched BL10 mice.