Figure 6: Vitamin E promotes membrane repair in intact skeletal muscle.

(a) Soleus muscle was excised and then with minimal delay laser injured (red arrow indicates the site of injury) in the presence of 5 mM hydrogen peroxide (H₂O₂). Wounding plus (calcium) and minus (no calcium) in the absence of H₂O₂ is also shown. One group of solei was treated with Trolox for 1 h before laser injury (Trolox). The confocal images depict myocyte staining before (0 s) and at two intervals (30 s and 445 s) after injury with FM 1-43 dye. (b) Measured FM dye influx (20 s intervals) for the four myocytes imaged above, injured in the absence of extracellular calcium (red triangles), in the presence of H₂O₂ (cyan squares), in the absence of H₂O₂ (black dots) and in the presence of H₂O₂ after Trolox pretreatment (magenta dots). Dips and rises in the fluorescence are observed due to muscle contractions that caused temporary lapses in focus. (c) Total dye uptake by myocytes in intact solei 445 s after laser injury under the conditions defined above. A significant (P<0.05; n=8) increase in dye uptake occurred in fibres exposed to H₂O₂ (blue bar) relative to unchallenged controls (red bar). Trolox pretreatment of H₂O₂ challenged cells (blue bar with diagonal stripes) significantly (P<0.05; n=10) decreased dye uptake compared with untreated H₂O₂ challenged cells (blue bar). Scale bars 20 μm.