Kinetics of locomotion of human granulocyte populations

The locomotor kinetics of human granulocytes under gradient and non-gradient conditions were studied with the Boyden micropore filter method using casein as a stimulant. The in-filter distribution for 3 different incubation times, and one-level counts for a wide range of incubation times were determined photographically. Under gradient ("chemotactic") conditions, the number of responsing granulocytes depended on the sharpness of the casein gradient, whereas the average migrational velocity of the population appeared to be constant. It was not possible, by comparison with a theoretical model, to demonstrate a directional migration towards increasing casein concentrations. The previously reported Gaussian distribution under non-gradient (chemokinetic) conditions, was confirmed. In these experiments the number of responding cells appeared to depend on the absolute casein concentration, while their average velocity seemed uninfluenced.