Figure 6.

The healing myocardium sequentially mobilizes two monocyte subsets. Infiltration of leucocyte into the infarct region (CD45⁺ cells A and B) was increased at day 3 and 7 post infarction for both the MC‐ and bone marrow (BM) cell‐implanted groups while no differences were seen in the medium alone group without cell transplantation, evaluated by immunofluorescent labelling (n = 3, *P < 0.05, **P < 0.01 versus medium alone). Infiltration of Ly‐6C^hi/CD11b⁺ monocytes peaked at 3 days post‐MI (C and E, n = 3, **P < 0.01 versus medium alone) whereas the Ly‐6C^lo/CD11b⁺ peaked at 7 days post‐MI (D and F, n = 3, *P < 0.05, **P < 0.01 versus medium alone) in both the MC and BM groups and was significantly higher in these groups compared to the medium‐injected control group. However, there was more mobilization of Ly‐6C^hi/CD11b⁺ monocytes in the MC group compared with the BM group at 3 and 7 days post‐MI (E, n = 3, **P < 0.01). On the other hand, there was more mobilization of Ly‐6C^lo/CD11b⁺ monocytes in the BM group compared with the MC group at 7 days post‐MI (F, n = 3, **P < 0.01); scale bar = 50 μm