Figure 3. TNFα blockade inhibited the loss of type II fast twitch fibers. (A) Percentage of Type II (left), Type IIB (middle) and Type I (right) fibers in GS muscles of 12 months old mice in controls (saline) or Etanercept-treated mice at 22 and 28 months of age, *=p<0.05, **= p<0.01 and ***=p<0.001. (B) Representative images of GS muscle sections. Type I fibers are blue, type IIA are green, type IIB are red. Scale bar=50 μm. (C) Percentage of Type II (left), Type IIB (middle) and Type I (right) fibers in soleus muscles of 12 months old mice or in control or Etanercept-treated mice at 22 and 28 months of age. *=p<0.05, **= p<0.01. (D) Representative images of soleus muscle sections. Scale bar=50 μm.