FIGURE 7.

Sympathetic innervation prevents skeletal muscle atrophy and SNS ablation leads to specific muscle fibre-subtype atrophy in GA and TA muscles. H&E staining of TA and GA muscles from sham (top) and sympathectomized (bottom) mice (A) showed significant reduction in mean CSA (B) and a shift towards smaller fibres in the relative-frequency histograms (C) (n = 4 mice, six muscles per group) (C). Representative cross sections of TA and GA muscles from sham (top) and sympathectomized (bottom) mice (D). Myofibre were immunostained with specific MHC antibodies to identify type-I (blue secondary Ab), -IIa (green), and –IIb (red) fibres. Fibres negative to these three antibodies were labelled IIx.⁴⁵ Panels E and F examine muscle fibre composition and muscle fibre CSA respectively. The number of fibres studied was 6249 in four GA muscles from four mice per group; 5603 in four TA from four mice per group, and 2525 in four soleus from three mice per group. Calibration bar = 100 μm. *P < 0.05, ^†P < 0.01 and ^‡P < 0.001