Possible physical-chemical mechanism of cell fusion in myogenesis of the skeletal muscle through intercellular pinocytosis

The authors propose a mechanism of cell fusion in the myogenesis of the skeletal muscle based on the capacity of the intercellular contacts formed with a five layer structure for invagination to the point of formation of free vesicles (intercellular pinocytosis) leading to expenditure of membrane material followed by perforation and destruction of the membrane in the region of union of the cells. It is assumed that the formation of the invaginations is associated with clustering of the proteins on one of the cytoplasmatic sides of the contact membrane and change in the Gibbs surface energy with the appearance of chemically induced and bending moments. A quantitative evaluation is given of the transition of the invagination (caveola) to the vesicle depending on the osmotic pressure gradient between the fusing cells determined by the mechanism of polymerization of the protein subunits during assembly of the contractile elements in one of the myogenic cells. © 1991.