INVITRO ALTERATIONS OF EPIDERMAL-CELL ADHESION INDUCED BY TEMPERATURE, SUBSTRATE, AND CATIONS

Epidermal cell-to-cell or basal cell-to-substrate adhesion in vitro, involves as yet, unknown mechanisms. The rate of attachment of newly dissociated neonatal mouse epidermal cells and the rate of keratinocyte detachment from preformed epidermal monolayers was investigated under a variety of experimental conditions. Variables such as temperature, nature of substrate and presence of cations in the growth medium were important in the initial cell-to-substrate attachment. Removal of Ca2+ and Mg2+ from the growth medium was associated with a very low attachment rate (< 5% at 24 h and 48 h). The initial cell-to-substrate attachment of epidermal cells decreased about 50% when maintained in medium deficient in either Mg2+ or Ca2+ indicating that both cations are important in the cell-to-substrate attachment. Keratinocyte-detachment from preformed monolayers increased in medium deficient in Ca2+, Mg2+ and in medium only deficient in Ca2+. Detachment in cultures maintained in Mg2+ deficient medium was similar to controls. Ca2+ is 1 factor that may regulate epidermal cell-to-cell and cell-to-substrate interactions in vitro. Mg2+ appears to influence also in the initial attachment process of epidermal basal cells.