The cellular events of injured muscle regeneration depend on the nature of the injury.
The cellular events of muscle degeneration and regeneration and their time course were studied in two experimental models of muscle injury mice; (i) the denervation-devascularization (DD) of the extensor digitorum longus (EDL) muscle, which is an ischaemic lesion; (ii) the injection of notexin (NOT), a snake venom, in the tibialis anterior (TA) muscle, resulting in a toxic lesion. Compared to the ischaemic lesion, the toxic lesion was characterized by a more extensive inflammatory infiltrate and a shortened phase of phagocytosis of the damaged myofibres. This allowed the proliferation and differentiation of muscle precursor cells (mpc) to take place earlier and may be further promoted by growth factors released by inflammatory cells. Compared to DD-EDL, NOT-TA showed also a greater conservation of the basement membranes of the necrotic myofibres, that can support the fusion of mpc into myotubes, and a better microvascularization. The onset of muscle regeneration is tightly related to the events which occur during the phase of degeneration.
Lefaucheur
J P
JP
Laboratoire de Physiologie, Atelier de Régéneration Neuromusculaire, Faculté de Médecine Saint-Antoine, Paris, France.
Sébille
A
A
D000818:Animals; D004546:Elapid Venoms / Q000633:toxicity; D007150:Immunohistochemistry; D007511:Ischemia / Q000473:pathology; D008297:Male; D051379:Mice; D009121:Muscle Denervation; D018485:Muscle Fibers, Skeletal / Q000502:physiology; D018482:Muscle, Skeletal / Q000098:blood supply / Q000293:injuries* / Q000473:pathology; D009135:Muscular Diseases / Q000139:chemically induced / Q000473:pathology*; D009498:Neurotoxins / Q000633:toxicity; D010587:Phagocytosis; D012038:Regeneration / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D013997:Time Factors
D004546:Elapid Venoms; D009498:Neurotoxins; C005082:notexin