Tissues of soleus muscle of animals subjected to muscle overuse coupled with injections of C + Th. There is a very marked inflammatory infiltrate in (A), most of the area shown being occupied by infiltrated white blood cells and loose connective tissue. There is an infiltration of white blood cells and a marked presence of connective tissue in-between muscle fibers in (B) and (C). The muscle fibers in (C) show frequently internal nuclei (arrows). In the inset in (A), two parallel sections stained with H&E (figure to the left) and stained for demonstration of CD31 (figure to the right), are shown. There are numerous CD31 reactions in the inflammatory/connective tissue area (triangles), reactions which based on what is known for CD31 are related to endothelia of blood vessels. Asterisks at muscle fibers. Bars = 100 μm (A), 50 μm (B, C).