Human neutrophil (PMN) oxygen radical production and the cytoskeleton.
Electron paramagnetic resonance (EPR) studies were conducted to examine oxygen radical generation following PMN activation by N-formyl-1-methionyl-1-leucyl-1-phenylalanine (fMLP) in the presence or absence of phalloidin and cytochalasin B (CB), agents which stabilize or disrupt f-actin, or taxol and colchicine which stabilize and disrupt microtubule cytoskeletal structures respectively. PMN oxyradical production was monitored using the spin trap 5,5-dimethyl-1-pyrroline n-oxide (DMPO). PMN when unstimulated, treated with phalloidin (10(-6)-10(-8)M), CB (10(-6)-10(-8)M), taxol (10(-6)-10(-8)M), or colchicine (10(-6)-10(-8)M), did not produce a detectable DMPO signal. Stimulation with fMLP (10(-6)M), however, resulted in a significant hydroxyl radical signal which was augmented by PMN treatment with CB (10(-6)-10(-7)M, p < 0.05) and attenuated following PMN treatment with phalloidin (10(-6)-10(-7)M, p < 0.05). Interestingly, colchicine treatment (10(-6)-10(-8)M) significantly attenuated fMLP-mediated oxyradical production, whereas taxol (10(-6)-10(-7)M) significantly increased PMN oxyradical production. These data suggest that stabilization of f-actin and disruption of microtubules attenuates the PMN oxidative burst, whereas disruption of f-actin and stabilization of microtubules increases radical production. These findings suggest cytoskeletal domain-specific contributions to PMN oxidative activity.
Wiles
M E
ME
Parke-Davis Pharmaceutical Research Division, Warner-Lambert Co., Ann Arbor, MI, USA.
Dykens
J A
JA
Wright
C D
CD
D000199:Actins / Q000494:pharmacology; D003571:Cytochalasin B / Q000494:pharmacology; D003599:Cytoskeleton / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D004789:Enzyme Activation; D006801:Humans; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D010590:Phalloidine / Q000737:chemistry; D016897:Respiratory Burst; D013481:Superoxides / Q000378:metabolism*
D000199:Actins; D013481:Superoxides; D010590:Phalloidine; D003571:Cytochalasin B; D009240:N-Formylmethionine Leucyl-Phenylalanine