title: Amiloride does not influence the capability of interferon gamma to potentiate superoxide anion and hydrogen peroxide release by human mononuclear phagocytes.
abstract: Since the molecular mechanisms of macrophage activation in response to interferon gamma (IFN-gamma) are still not well defined we have investigated whether amiloride, a specific inhibitor of the Na+/H+ antiporter, had any effect on the IFN-gamma-mediated potentiation of human monocyte and monocyte-derived macrophage capability to produce O2- (respiratory burst). Here, we demonstrate that amiloride neither inhibits the capability of IFN-gamma to activate the mononuclear phagocyte respiratory burst nor influences IFN-gamma induction of steady-state mRNA levels for 2 components of the superoxide anion-generating enzyme system. On the contrary, we show that IFN-gamma-enhanced expression of the HLA-DR alpha gene is significantly inhibited by amiloride These data indicate that Na+/H+ antiporter stimulation by IFN-gamma is not involved in the mechanism of activation of macrophage oxidative metabolism.
authors.affiliation: Institute of General Pathology, University of Verona, Italy.
authors.forename: M A
authors.initials: MA
authors.lastname: Cassatella
authors.forename: D
authors.initials: D
authors.lastname: Peroni
authors.forename: M A
authors.initials: MA
authors.lastname: Amezaga
authors.forename: F
authors.initials: F
authors.lastname: Vicentini
authors.forename: F
authors.initials: F
authors.lastname: Bazzoni
mesh_terms: D000584:Amiloride / Q000494:pharmacology*; D002352:Carrier Proteins / Q000378:metabolism; D004347:Drug Interactions; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000494:pharmacology*; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D009000:Monocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D010586:Phagocytes / Q000187:drug effects* / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers; D013481:Superoxides / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D017923:Sodium-Hydrogen Exchangers; D013481:Superoxides; D000584:Amiloride; D007371:Interferon-gamma; D006861:Hydrogen Peroxide