Kinetic studies of cell migration in a modified Boyden chamber: dependence on cell concentration and effects of the chymotrypsin-like cationic protein of human granulocytes.

Migration of PMN cells was measure kinetically by the "leading front" method in a modified Boyden chamber. In some experiments, release of lactoferrin and of chymotrypsin-like cationic protein were measured simultaneously. Migration, both directed and random, was increased by increased cell concentration. Kinetically, directed migration consisted of two phases. The second phase was more influenced by the cell concentration. Preincubation of the cells with low concentrations of chymotrypsin-like cationic protein stimulated cell migration in the same way as did high cell concentrations, i.e., by primarily affecting the second phase. The effect of chymotrypsin-like cationic protein was time and dose dependent and dependent on the chymotrypsin-like activity of the protein. At high concentrations of protein, the cells were immobilized. Release of granular proteins did not take place during the first phase of migration but was parallel to the second phase. It is concluded that chymotrypsin-like cationic protein might be one of the substances responsible for the effect of cell concentration seen on migration in vitro.