Studies on the mechanism of cell attachment to a substratum with serum in the medium: Further evidence supporting a requirement for two biochemically distinct processes

Treatment of baby hamster kidney cells with cytochalasin B or omission of divalent cations from the culture medium are conditions resulting in an inhibition of cell attachment at rest; however, these conditions do not result in inhibition of cell attachment in a centrifugal field. In marked contrast, treatment of cells with trypsin or with tranquilizers such as fluphenazine results in an inhibition of cell attachment at rest or in a centrifugal field. The evidence is interpreted to indicate that cell adhesion involves at least two biochemical processes: formation of the adhesive bond per se (inhibited by tranquilizers or trypsin) and a mechanical process of cell-to-substratum contact and/or spreading (inhibited by cytochalasin B or omission of divalent cations from the medium).