Cytochalasin B-induced superoxide production in polycation-treated neutrophils.
Cytochalasin B alone induces little superoxide production in intact rabbit peritoneal neutrophils. The cytochalasin causes a strong production of superoxide in cells treated with membrane-permeabilizing polycations. Several polycations were able to express the activating effect of cytochalasin B. Especially the poly-L-arginine with a molecular weight of 24,000 proved to be effective. The effectiveness of some polycations is limited because they inactivate the superoxide-generating oxidase system of the neutrophil. Cytochalasin B-induced superoxide production starts at poly-L-arginine concentrations that cause a change of membrane permeability. At the concentrations of cytochalasin B used in our experiments, the binding of [3H]cytochalasin B is not enhanced in poly-L-arginine-treated cells as compared with control cells. Activation of superoxide production by cytochalasin B in polycation-treated neutrophils occurs both in the presence or absence of extracellular Ca2+. When the cells are pretreated with agents that known to interfere with intracellular Ca2+, the subsequent activation is strongly inhibited, suggesting a role for intracellular Ca2+ in cytochalasin B-induced activation. It is suggested that cytochalasin B alone is not able to activate all the steps that eventually result in complete activation of the superoxide-generating oxidase and that membrane perturbation by polycation provides activation of the remaining steps.
Elferink
J G
JG
Department of Medical Biochemistry, University of Leiden, The Netherlands.
de Koster
B M
BM
Boonen
G J
GJ
D000595:Amino Acid Sequence; D000634:Aminoquinolines / Q000097:blood; D000818:Animals; D002118:Calcium / Q000502:physiology; D003571:Cytochalasin B / Q000378:metabolism / Q000494:pharmacology*; D005456:Fluorescent Dyes; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D010455:Peptides / Q000494:pharmacology; D011073:Polyamines; D000071228:Polyelectrolytes; D011108:Polymers / Q000494:pharmacology*; D011817:Rabbits; D011869:Radioligand Assay; D016897:Respiratory Burst / Q000187:drug effects; D013050:Spectrometry, Fluorescence; D013481:Superoxides / Q000378:metabolism*
D000634:Aminoquinolines; D002118:Calcium; D003571:Cytochalasin B; D005456:Fluorescent Dyes; D007770:L-Lactate Dehydrogenase; D010455:Peptides; D011073:Polyamines; D000071228:Polyelectrolytes; D011108:Polymers; D013481:Superoxides; C015462:polyarginine; C035739:Quin2