Trypsinized BHK21 cells aggregate in the presence of metabolic inhibitors and in the absence of divalent cations.

The rapid formation of adhesions in suspension by lightly trypsinized BHK21 cells is not dependent on protein synthesis, and only in part on cellular metabolism, although it is completely inhibited by heat- and aldehyde-fixation of the cells. A requirement for protein synthesis becomes evident only if cells are exposed to high levels of trypsin for long periods. Formation of adhesions does not require addition to the medium of divalent cations, although it is increased by divalent manganese and cobalt ions. It is promoted by cytochalasin B and by cyclic AMP and is not inhibited by p-mercuriphenylsulphonate. We discuss a possible relationship between aggregation and the formation of gap junctions.