Cytochalasin B III. Inhibition of Human Polymorphonuclear Leukocyte Phagocytosis1

Cytochalasin B (CB), a metabolic product of Helminthosporium dematioideum has been shown to inhibit cytoplasmic division of mammalian (1-4) and Xenopus laevis eggs (5). Nuclear division proceeds normally in cells in the presence of CB. This results in disassociation of cytoplasmic and nuclear division and multinucleated cells are produced (1). Cytoplasmic division (cytokinesis) can be thought of as occurring in three phases, i.e., division of the nucleus, furrowing of the membranes, and fusion of membranes. It has been demonstrated that nuclear division proceeds normally (1-4) and furrowing is not affected (5) in the presence of CB. Therefore, fusion of membranes seems to be the target of drug action. Since membrane fusion also occurs in the process of phagocytosis we were interested in testing the effect of CB on this function of polymorphonuclear leukocytes. We report here the inhibition of bacterial phagocytosis by human polymorphonuclear leukocytes in the presence of Cytochalasin B.Materials and Metho...