Unilateral Muscle Overuse Causes Bilateral Changes in Muscle Fiber Composition and Vascular Supply
Figure 5
Bilateral changes in vascular supply in affected areas in the exercised and non-exercised gastrocnemius and soleus muscles.
Serial cross-sections from a control (A, F), an exercised (B, G) and non-exercised (C, H) gastrocnemius (GA) muscle and an exercised (D, I) and non-exercised (D, H) soleus (SOL) muscle. The cross-sections A–E are stained for mAb M0823 (CD31) against endothelium in vessels and the merged sections E–J are stained for CD31 (yellow/green), pAb PC128 against laminin (red) and DAPI (stains nuclei blue). Sections A, F show a control with a normal pattern of capillaries around fibers whereas section B–E, F–J shows different patterns of changes in capillarization in areas with inflammation and fibrosis. The samples from the exercised and non-exercised GA muscles shows examples of low capillary density in an area with inflammation/fibrosis (B, G) and in an area with mainly fibrosis (C, H). The sample from the exercised soleus muscle (D, I) shows an example of increased number of vessels with a larger size than capillaries in an area with fibrosis, inflammation and degenerating/regenerating fibers. The sample from the non-exercised SOL (E, J) shows an area with severe inflammation and increased capillarization. The differences in vascularization patterns probably represent different stages in the degenerative/regenerative process in the muscles. Arrows point at immunoreactions for capillaries and arrowheads against larger vessels in each section. Scale bar 50 µm.