Fig. 1.

The 9-mo-old mdx hearts have significantly more scarring compared with C57BL/10 hearts. A: representative images of sirius red/fast green staining in bright-field and cross-polarized light illumination of hearts from 9-mo-old C57BL/10 and mdx mice from both the right and left ventricles. Collagen appears red in bright-field sections and the birefringence of these lesions further confirms the collagen content of this staining. Note that collagen staining in C57BL/10 hearts is primarily perivascular with some interstitial staining, while mdx hearts have more intense interstitial staining and scar formation. Bar is 100 μm. B: hearts from mdx mice show significantly higher levels of fibrosis. ‡P < 0.0001 vs. C57BL/10; data obtained from heart sections from 14 C57BL/10 and 15 mdx mice.