Fig. 2

Distribution of iNOS and NADPH-d in DMD muscle. Transverse serial cryostat sections (10-µm thick) of a deltoid muscle from DMD patient immunostained by iNOS antibody (first column, upper row; third column, first row), developmental myosin heavy chain antibody, d-MHC (first column, second row; fourth column lower row), complement membrane attack complex C5b-C9, MAC (second column, lower row; third column, second row), stained for NADPH-d reactivity (second and fourth columns, first row) and succinate dehydrogenase activity (second and fourth columns, second row). Double immunofluorescence staining was realized using dual filters (first and fourth columns, lower row). First column: iNOS-positive fibers colocalized with muscle fibers expressing d-MHC. Second column: whenever the SDH activity is low in the small fibers double-immunostained for iNOS and d-MHC, NADPH-d reactivity is higher in these fibers. No immunoreactivity was shown for MAC. Third column: Some necrotic fibers, immunostained by anti-MAC antibody, were stained with anti-iNOS antibody. Fourth column: NADPH-d reactivity and SDH activity were not present in degenerating muscle fibers. Note that some mononuclear cells were reactive for NADPH-d. Few fibers were d-MHC positive.