Oscillatory motion in human neutrophils responding to chemotactic stimuli

Human neutrophils treated with the secretion inhibitor 17-hydroxywortmannin were stimulated with fMLP, C5a, PAF or LTB4, and the ensuing shape change was studied. The cells rapidly extended lamellipodia and showed regular oscillatory behaviour. The oscillations were observed in both light transmission and 90 degrees light scattering, had the same frequency in each case, and disappeared within 30-50 seconds. Light scattering theory suggests that they reflect rhythmic changes in the shape and/or size of the chemotactically stimulated cells, possibly related to crawling or swimming movements associated with migration.