Figure 6.

Morphometric comparisons between untreated adult nondystrophic and mdx TS muscles. (A) Regional differences in fiber density (number of fibers per μm length TS) in nondystrophic (black histobars) and mdx (gray histobars) TS muscles. Note the cephalad to caudal gradient in density for the mdx preparations (τττ − p<0.001) and the increase in fiber density for the middle region of mdx TS muscles (* - p<0.05). (B) Regional differences in Feret's diameter (μm) in nondystrophic (black) and mdx (gray) TS muscles. Note the cephalad to caudal gradient in diameter for the mdx preparations (τ − p<0.05) and the reduction in diameter for all regions of the mdx TS muscle (** - p<0.01; *** - p<0.001). (C) Regional differences in fiber cross sectional area (μm²) in nondystrophic (black) and mdx (gray) mice. Note the cephalad to caudal gradient in fiber cross sectional area for mdx mice (τ − p<0.05) and the reduction in fiber cross sectional area in all regions of the mdx TS (*** - p<0.001). (D) Regional differences in total working area (μm²) per micron length of TS for both nondystrophic (black) and mdx (gray) mice. Note the cephalad to caudal gradient in working area for both preparations (τ - p<0.05, ττ − p<0.01) and the decrease in working area in the middle and cephalad regions of the mdx TS (** - p<0.01). N equals the number of preparations (mice).