Résumé :
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The main constraint of the therapeutic strategy of intramuscularly injecting myogenic cells is that the implanted cells fuse only with the myofibers reached by the injection trajectories. An intravascular delivery of myogenic cells may be obviously a better strategy of cell delivery, but so far this strategy seemed to work only with special cells such as the so-called “mesoangioblasts”. Previous experiments of intravascular delivery of myoblasts in mice produced limited results, but this animal model is quite different from human in several aspects of the myoblast transplantation biology. According to our experience, nonhuman primates are more appropriate models for human extrapolations in this field: transplantation biology and myoblast culture are very similar. Thus, we performed intra-arterial injections of beta-galactosidase-labeled allogeneic myoblasts in tacrolimus-immunosuppressed cynomolgus monkeys. The myoblast suspension was injected in one femoral artery. Some muscles were damaged with a 27G needle 3 days before or at the time of the cell infusion. Several organs and muscles were biopsied 1 hour, 1 day and 1 month post-transplantation, and the biopsies were analyzed by histology. We observed that most intra-arterial delivered myoblasts were retained mainly in the capillaries of the skeletal muscles of the leg ipsilateral to the cell injection. Scarce beta-galactosidase-positive cells were observed in the lungs only at 1 hour post-transplantation, and no beta-galactosidase-positive cells were observed in other organs (liver, brain, spleen, heart, gut) or other muscles. One month post-transplantation, beta-galactosidase-positive myofibers were observed only in the skeletal muscles of the ipsilateral leg to the injection, when these muscles were damaged at the time of the cell injection.
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