OPPOSITE EFFECT OF CYTOCHALASIN-B ON AGONIST-INDUCED RESPIRATORY BURST IN NEUTROPHILS AND MONOCYTES

The effects of cytochalasin B on the respiratory burst, calcium transients and cell shape change of neutrophils and monocytes has been studied. Cytochalasin B enhanced fMLP-induced respiratory burst in neutrophils whereas the opposite effect, i.e. an inhibition close to 50%, was elicited in fMLP-stimulated monocytes. The differences did not depend on calcium homeostasis. On the basis of cell shape changes, and the well known effect of cytochalasin B on actin polymerization, the opposite effects of cytochalasin B could stem from differences between both cell types concerning the pattern of cytoskeleton-membrane interaction which could affect the recruitment and assembly of membrane-bound or cytosolic components of NADPH-oxidase.