Fig. 5. Toluidine-Blue-stained, longitudinal semithin section of adductor longus muscle fibers from a rat orbited in microgravity for 2 weeks in Cosmos biosatellite mission 2044 and returned to terrestrial gravity loading for approximately 10h before tissue fixation. The central muscle fiber exhibits large and small lighter-stained foci of sarcomere eccentric-like contraction damage, representing myofilament disruption. Sarcomere lesions were detected in 44% of the fibers examined. Scale bar, 42µm.