Fig. 7.

Effect of dexamethasone (Dex) treatment on histopathology of quadriceps muscles of BLA/J mice (aged 10 months). Representative images of consecutive paraffin sections showing highly variable histopathology of (i) BLA/J and (ii) BLA/J + Dex quadriceps stained by (A, B) haematoxylin and eosin (H&E), indicating the location of some adipocytes (circled), foci of inflammatory cells (arrowheads), and large pale myofibres (asterisks, *). C, D The presence of glycogen is shown by periodic acid-Schiff (PAS) staining, with (E, F) the absence of glycogen following diastase-induced breakdown (as a control to verify glycogen PAS staining; PAS-D). More (G, H) PAS-stained sections are shown from additional BLA/J mice. Dex treatment (in B, D, and H) appeared to increase the number of large pale myofibres (some marked by *), and some with conspicuous vacuoles/fragmentation (arrows) evident with PAS staining. In contrast, such pale myofibres did not appear as large (nor vacuolated) in untreated BLA/J muscle. Shown for four 10-month-old male mice: (i) BLA/J (ID for panels A, C, E. 16/21, and G. 16/23) and (ii) BLA/J + Dex (ID for panels B, D, F. 16/32, and H. 16/31). Scale bar = 100 μm