Electrical properties and ability to form low-resistance junctions in rat neoplastic cells LW13K2 and RsK4

Clonal lines of Lewis rat neoplastic fibroblastoid LW13K2 cells and epithelioid RsK4 cells were used to study the changes in membrane potential, input resistance and the capability to form low-resistance junctions upon RSV transformation. The drop of MP in RsK4 cells was accompanied by the acquisition of temperature dependence. The input resistance was simultaneously increased. This was considered to be a consequence of the decrease in potassium current across the cell membrane and of a change in the mechanism of potassium transport which became energy dependent. Examination of fluorescent tracer (n.w. 330) diffusion which was negative in the homotypic situation in both cell lines confirmed only the relative independence of these cells in culture. In the heterotypic situation LW13K2 in contact with normal mouse embryo fibroblasts gave positive results whereas RsK4 were almost negative.