[The effect of the components of the extracellular matrix on the spreading of rat keratinocytes in the substrate during cultivation in a low-calcium medium].

Two-day-old newborn rat keratinocytes were plated in serum-free low-Ca medium on different substrates. The culture conditions prevented from keratinocyte aggregation, and therefore allowed to observe the interaction between a single cell and the substrate without interference of cell-cell contacts. It is shown that separate cells spread on type I collagen, whereas cell colonies developed on fibronectin and non-treated glasses. Cellular actin distribution, revealed by rhodamine-phalloidin staining, suggested that on type I collagen cell-substrate interactions differed from those on other substrates. While cells on type I collagen had large radial phillopodia with rich actin staining, they had marginal actin rings and small phillopodia plated on fibronectin or glass. Taking together differences in cytoskeletal actin distribution and shapes of colonies type I collagen is supposed to be more powerful than fibronectin and glass in binding the corresponding cell receptors, thus preventing from colony formation.