Representative images from unstimulated and stimulated TA muscles from P188-treated and control 9–11 month old female mdx mice.

<p>After muscle isometric force measurements and the eccentric contraction protocol were completed mice were immediately euthanised and dissected. The stimulated and unstimulated TA muscles were mounted in the same block, cryosectioned and stained with H&E, Alizarin red and biotinylated anti-mouse IgG antibody followed by nickel-enhanced DAB). Representative low power images of serial sections from a single mouse from each treatment group are shown above. For each stain the upper row is images of the unstimulated TA (U) and the lower row is images of the stimulated TA muscle (S) from the same mouse. While there appears to be a mild reduction in H and E score (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0091221#pone.0091221.s001" target="_blank">Figure S1</a>) in the unstimulated muscle from the 30 mg/kg P188 group this difference is not seen in the stimulated muscles. Similarly there are less IgG positive fibres (dark grey) in the unstimulated muscles of the P188-treated group but not in the stimulated muscles. For all treatment groups stimulated muscles are expanded by marked oedema and contain greater numbers of hypercontracted (densely eosinophilic and rounded), alizarin red positive (bright red) and IgG positive (dark grey) fibres. Scale bars represent 1000 µm.