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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1994-8-4
pubmed:abstractText
Phagocytes are able to generate reactive oxygen species by an activatable NADPH oxidase system. We investigated the inhibition of NADPH oxidase activation by a methoxy-substituted catechol, apocynin. Oxygen uptake by neutrophils incubated with 300 microM apocynin was completely inhibited at 7 min after addition of serum-treated zymosan (STZ), with a lagtime of inhibition of 2 to 3 min. The lagtime of effect of apocynin in neutrophils relatively deficient of myeloperoxidase was about 50% longer when compared with normal cells. Inhibition of the STZ-induced respiratory burst by apocynin was also observed in human eosinophils but not in human alveolar macrophages. Immunoblots of neutrophil membranes, isolated at 2 and 7 min after STZ stimulation of neutrophils, demonstrated translocation of the cytosolic oxidase components p47-phox and p67-phox to the membrane fraction. Translocation at 7 min after STZ stimulation was markedly reduced when the neutrophils had been incubated with 300 microM apocynin, but translocation was normal after 2 min of stimulation. These properties suggest that apocynin is an intracellular inhibitor of the assembly of NADPH oxidase in neutrophils and eosinophils and that apocynin requires conversion by peroxidases to exert its inhibitory effect. The capacity of neutrophils for intracellular killing of Staphylococcus aureus was not affected by apocynin. The potential therapeutic value of apocynin was demonstrated in vitro by its ability to protect secretory leukocyte proteinase inhibitor from oxidative inactivation by neutrophils.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1044-1549
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
95-102
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:8018341-Acetophenones, pubmed-meshheading:8018341-Anions, pubmed-meshheading:8018341-Blood, pubmed-meshheading:8018341-Blood Bactericidal Activity, pubmed-meshheading:8018341-Cell Membrane, pubmed-meshheading:8018341-Enzyme Activation, pubmed-meshheading:8018341-Eosinophils, pubmed-meshheading:8018341-Humans, pubmed-meshheading:8018341-Hydrogen Peroxide, pubmed-meshheading:8018341-Immunoblotting, pubmed-meshheading:8018341-Kinetics, pubmed-meshheading:8018341-NADH, NADPH Oxidoreductases, pubmed-meshheading:8018341-NADPH Oxidase, pubmed-meshheading:8018341-Neutrophils, pubmed-meshheading:8018341-Oxygen, pubmed-meshheading:8018341-Peroxidase, pubmed-meshheading:8018341-Phagocytes, pubmed-meshheading:8018341-Protease Inhibitors, pubmed-meshheading:8018341-Respiratory Burst, pubmed-meshheading:8018341-Staphylococcus aureus, pubmed-meshheading:8018341-Superoxides, pubmed-meshheading:8018341-Zymosan
pubmed:year
1994
pubmed:articleTitle
Characteristics of the inhibition of NADPH oxidase activation in neutrophils by apocynin, a methoxy-substituted catechol.
pubmed:affiliation
Department of Pulmonology, University Hospital Leiden, The Netherlands.
pubmed:publicationType
Journal Article