title: Stimulation and inhibition of nitric oxide production in macrophages and neural cells as observed by spin trapping.
abstract: We have combined electron paramagnetic resonance (EPR) and spin trapping techniques to measure nitric oxide (NO) production by activated macrophages and neural cells in vitro. Macrophages stimulated by bacterial lipopolysaccharide (LPS), gamma interferon (IFN gamma), or both, produced NO. Differentiated and undifferentiated neural cells activated by KCl and CaCl2, N-methyl-D-aspartate (NMDA), and IFN gamma were shown to produce NO as well. The mechanism of activation in neural cells could be either by channels or receptors. Maximum NO production in macrophages was achieved when stimulated by a combination of LPS and IFN gamma administered sequentially or concurrently. IFN gamma was the most effective stimulant for neural cells. The in vitro production of NO by all these cells was inhibited by NG-monomethyl L-arginine (L-NMMA) in a dose-dependent manner. Complete inhibition of NO production occurred when cells were grown in L-arginine free medium, indicating that L-arginine was essential for NO production. We also concluded from our study that NO production in macrophages was in greater amounts and more long lasting in duration than that observed in the neural cells.
authors.affiliation: College of Medicine, University of Illinois, Urbana 61801, USA.
authors.forename: S W
authors.initials: SW
authors.lastname: Norby
authors.forename: J A
authors.initials: JA
authors.lastname: Weyhenmeyer
authors.forename: R B
authors.initials: RB
authors.lastname: Clarkson
mesh_terms: D000818:Animals; D002122:Calcium Chloride / Q000494:pharmacology; D002460:Cell Line; D004578:Electron Spin Resonance Spectroscopy; D007371:Interferon-gamma / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008262:Macrophage Activation / Q000502:physiology*; D051379:Mice; D016202:N-Methylaspartate / Q000494:pharmacology; D009447:Neuroblastoma; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis*; D016716:PC12 Cells; D051381:Rats; D019097:Spin Trapping; D013268:Stimulation, Chemical; D014407:Tumor Cells, Cultured
chemical_list: D008070:Lipopolysaccharides; D009569:Nitric Oxide; D016202:N-Methylaspartate; D007371:Interferon-gamma; D002122:Calcium Chloride