Fig. 3

Impact of intramuscular administrations of 40% DMSO, 40% PG, IGF-1, and 2% trypsin on skeletal muscle regenerative capacity during the regenerative phase. a Representative images of skeletal muscle regeneration regulatory proteins (EbMHC and myogenin) and CD31 protein expression compared to no vehicle. Images were captured at ×200 magnification, scale bars = 50 µm. b Representative images of EbMHC, myogenin, and CD31 protein expression in the defective areas at ×400 magnification (serial sections are denoted by asterisks), scale bars = 50 µm. Arrows and arrowheads indicate the localization of nascent regenerating muscle fibers with robust EbMHC and myogenin protein expression, respectively. Laminin and dystrophin were applied to delineate regenerating muscle fiber structure and nuclei were visualized with DAPI