Fig. 9

The administration of interleukin 6 into ischemic muscle increases the number of new blood vessels but not the macrophages infiltration. The representative images of H&E staining of the transverse sections of the gastrocnemius muscle after PBS⁻ (a), mouse recombinant interleukin 6 (b), human recombinant interleukin 6 (c), mADSC (d), and hADSC (e) injection on day 7 post surgery. Several necrotic muscle fibers (black arrows) were observed in muscles after the administration of PBS⁻ (a) human recombinant interleukin 6 (c) and mADSC were observed? (d). Many necrotic muscle fibers with pale cytoplasm and the irregular internal architecture were observed in muscles after the administration of mouse recombinant interleukin 6 (b). Regenerative small muscle fibers with one or more centrally located nuclei (white arrows) were observed only in the muscles after hADSCs administration (d). The representative images of M2 macrophages (F4/80⁺ (red)/CD206⁺ (green)) after PBS⁻, mIL-6, hIL-6, mADSC, and hADSC injection on the seventh day after the surgery (f, g, h, i, j). The number of capillaries (CD31⁺) (l) and the total area of F4/80 macrophages (k) counted in collected muscles 7 days after the administration of hADSC, mouse and human recombinant interleukin 6, and PBS. n = 5; 5 muscles per group were analyzed; 5 (for the total area of F4/80) or 10 (for the number of capillaries) pictures of each muscle were taken. *p < 0.05, ***p < 0.001 evaluated with Kruskal-Wallis one-way analysis of variance and multiple comparison of mean ranks for all groups. Nuclei stained with DAPI (blue), scale bars = 50 μm