title: Hydrogen peroxide increases the phagocytic function of human neutrophils by calcium mobilisation.
abstract: We have studied the effect of exogenous administration of hydrogen peroxide (H(2)O(2)) on phagocytic activity of human neutrophils. The treatment of cells with increasing concentrations of H(2)O(2) evoke a significant elevation of phagocytic function assayed as phagocytic index, percentage and efficiency; and was similar to that induced by the calcium mobilising agonist formyl-methionyl-leucyl-phenylalanine (fMLP). This stimulatory effect was reduced by pre-treatment of neutrophils with catalase and abolished in neutrophils loaded with the intracellular calcium quelator dimethyl BAPTA. In the absence of extracellular calcium, treatment of cells with H(2)O(2) resulted in a increase in [Ca(2+)]( i ), indicating the release of calcium from intracellular stores. H(2)O(2) abolished the typical calcium release stimulated by the physiological agonist fMLP, while depletion of agonist-sensitive calcium pools by fMLP was able to prevent H(2)O(2)-induced calcium release. We conclude that H(2)O(2) induces calcium release from agonist-sensitive stores and consequently increase the phagocytosis process.
authors.affiliation: Department of Physiology, Faculty of Science, University of Extremadura, Av. De Elvas s/n, Badajoz 06071, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Bejarano
authors.forename: M P
authors.initials: MP
authors.lastname: Terrón
authors.forename: S D
authors.initials: SD
authors.lastname: Paredes
authors.forename: C
authors.initials: C
authors.lastname: Barriga
authors.forename: A B
authors.initials: AB
authors.lastname: Rodríguez
authors.forename: J A
authors.initials: JA
authors.lastname: Pariente
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002118:Calcium / Q000378:metabolism*; D002614:Chelating Agents / Q000737:chemistry / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016877:Oxidants / Q000494:pharmacology*; D010587:Phagocytosis / Q000187:drug effects* / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D002614:Chelating Agents; D016877:Oxidants; D017382:Reactive Oxygen Species; D004533:Egtazic Acid; D009240:N-Formylmethionine Leucyl-Phenylalanine; D006861:Hydrogen Peroxide; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium