Fig. 4

Immunofluorescence staining of CD31 in muscle vessels and electron microscopy of capillaryultrastructure. The CD31 immunofluorescence (red) region was increased in the exosome treatment group B compared to the PBS group A. C Quantitative analysis of CD31 fluorescence intensity on the 28 th day vs PBS, *P < 0.05. D. In PBS group the capillary lumen was narrow, the gap of endothelial cell was widened, and fingerlike protrusion and the pinocytotic vesicles in endothelial cells were increased and the mitochondria swelling, cristae shedding, vacuolar changes, intearity destruction. Endothelial space widened. E. In the exosome group.capillary lumen was smooth the gap of endothelial cells was nomal. The surface of endothelial cells was smooth and complete