Changes of cell surface configuration and regulation of cell proliferation.

The electric surface charge configuration of 3T3 and SV40-3T3 cells was characterized by determining the product of electrophoretic mobility of the cells times the viscosity of suspension medium. This quantity could be shown to change with temperature and/or treatment with calf serum or trypsin in close correlation with the effects of these agents on characteristics of cell proliferation. The present results, taken together with those of earlier studies on cell-electrophoresis and characterization of lipid constituents of the cells, support the hypothesis of a lateral phase separation in the plasmamembrane as triggering process in stimulation of proliferation of resting normal cells.