Translational movements of macrophages through media of different viscosities

The extent of the migration of guinea-pig peritoneal macrophages from capillary tubes over the surfaces of plastic Petri dishes, was quantitated by planimetry. It was observed that the amount of migration decreased as the viscosity of the medium was increased by the addition of agarose. An essential component of translational movement is the formation of adhesions between cells and their substrata. It is suggested on the basis of the present migration and adhesion experiments, that the increased viscosity reduces migration by retarding the formation of adhesions between the cells and their substrata. The experiments do not support the suggestion that agarose adsorbed to the dish surface affects the adhesion-dependent arm of migration or that viscous 'drag' on whole cells (over the viscosity range of 0.71 to 3.9 x 10(-3) N s m-2) reduces their movements.