ABSTRACT
Objective To investigate the whole differentiating process of myogenic satellite cells in vitro,and the expression of N-ACh receptors.Methods Skeletal muscle satellite cells were isolated by trypsin digestion in vitro and purified by preferential attachment method.The cells were observed morphologically and identified by ?-sarcomeric actin,desmin and skeletal myosin antibodies.Contraction of myotubes was observed after adding ACh in the culture medium, N-AChRs in myotube were also be identified by bungarotoxin.Results Cultured satellite cells in vitro differentiated into myoblasts and fused to form myotubes later.These cells were positive by ?-sarcomeric actin, skeletal myosin and desmin antibodies' staining.Adding ACh directly in the medium stimulated the contraction of myotubes.No obvious expression of ACh receptors was observed on the surface of satellite cells.Cluster of receptors aggregated on myotubes from neonatal rats' satellite cells cultured in differentiation media.Conclusion The myotubes differentiated from myogenic satellite cells have the function of contraction.N-ACh receptors were synthesized gradually during the process of differentiation.