Abstract
A reaction-diffusion model was developed to predict the fate of nitric oxide (NO) released by cells of the immune system. The model was used to analyze data obtained previously using macrophages attached to microcarrier beads suspended in a stirred vessel. Activated macrophages synthesize NO, which is oxidized in the culture medium by molecular oxygen and superoxide (O2-, also released by the cells), yielding mainly nitrite (NO2-) and nitrate (NO3-) as the respective end products. In the analysis the reactor was divided into a "stagnant film" with position-dependent concentrations adjacent to a representative carrier bead and a well-mixed bulk solution. It was found that the concentration of NO was relatively uniform in the film. In contrast, essentially all of the O2- was calculated to be consumed within approximately 2 microm of the cell surfaces, due to its reaction with NO to yield peroxynitrite. The decomposition of peroxynitrite caused its concentration to fall to nearly zero over a distance of approximately 30 microm from the cells. Although the film regions (which had an effective thickness of 63 microm) comprised just 2% of the reactor volume and were predicted to account for only 6% of the NO2- formation under control conditions, they were calculated to be responsible for 99% of the NO3- formation. Superoxide dismutase in the medium (at 3.2 microM) was predicted to lower the ratio of NO3- to NO2- formation rates from near unity to <0.5, in reasonable agreement with the data. The NO3-/NO2- ratio was predicted to vary exponentially with the ratio of O2- to NO release rates from the cells. Recently reported reactions involving CO2 and bicarbonate were found to have important effects on the concentrations of peroxynitrite and nitrous anhydride, two of the compounds that have been implicated in NO cytotoxicity and mutagenesis.
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- Caulfield J. L., Singh S. P., Wishnok J. S., Deen W. M., Tannenbaum S. R. Bicarbonate inhibits N-nitrosation in oxygenated nitric oxide solutions. J Biol Chem. 1996 Oct 18;271(42):25859–25863. doi: 10.1074/jbc.271.42.25859. [DOI] [PubMed] [Google Scholar]
- Denicola A., Freeman B. A., Trujillo M., Radi R. Peroxynitrite reaction with carbon dioxide/bicarbonate: kinetics and influence on peroxynitrite-mediated oxidations. Arch Biochem Biophys. 1996 Sep 1;333(1):49–58. doi: 10.1006/abbi.1996.0363. [DOI] [PubMed] [Google Scholar]
- Fridovich I. The biology of oxygen radicals. Science. 1978 Sep 8;201(4359):875–880. doi: 10.1126/science.210504. [DOI] [PubMed] [Google Scholar]
- Huie R. E., Padmaja S. The reaction of no with superoxide. Free Radic Res Commun. 1993;18(4):195–199. doi: 10.3109/10715769309145868. [DOI] [PubMed] [Google Scholar]
- Imlay J. A., Fridovich I. Assay of metabolic superoxide production in Escherichia coli. J Biol Chem. 1991 Apr 15;266(11):6957–6965. [PubMed] [Google Scholar]
- Iyengar R., Stuehr D. J., Marletta M. A. Macrophage synthesis of nitrite, nitrate, and N-nitrosamines: precursors and role of the respiratory burst. Proc Natl Acad Sci U S A. 1987 Sep;84(18):6369–6373. doi: 10.1073/pnas.84.18.6369. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Koppenol W. H., Moreno J. J., Pryor W. A., Ischiropoulos H., Beckman J. S. Peroxynitrite, a cloaked oxidant formed by nitric oxide and superoxide. Chem Res Toxicol. 1992 Nov-Dec;5(6):834–842. doi: 10.1021/tx00030a017. [DOI] [PubMed] [Google Scholar]
- Lancaster J. R., Jr Diffusion of free nitric oxide. Methods Enzymol. 1996;268:31–50. doi: 10.1016/s0076-6879(96)68007-0. [DOI] [PubMed] [Google Scholar]
- Lancaster J. R., Jr Simulation of the diffusion and reaction of endogenously produced nitric oxide. Proc Natl Acad Sci U S A. 1994 Aug 16;91(17):8137–8141. doi: 10.1073/pnas.91.17.8137. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lewis R. S., Deen W. M. Kinetics of the reaction of nitric oxide with oxygen in aqueous solutions. Chem Res Toxicol. 1994 Jul-Aug;7(4):568–574. doi: 10.1021/tx00040a013. [DOI] [PubMed] [Google Scholar]
- Lewis R. S., Tamir S., Tannenbaum S. R., Deen W. M. Kinetic analysis of the fate of nitric oxide synthesized by macrophages in vitro. J Biol Chem. 1995 Dec 8;270(49):29350–29355. doi: 10.1074/jbc.270.49.29350. [DOI] [PubMed] [Google Scholar]
- Licht W. R., Tannenbaum S. R., Deen W. M. Use of ascorbic acid to inhibit nitrosation: kinetic and mass transfer considerations for an in vitro system. Carcinogenesis. 1988 Mar;9(3):365–372. doi: 10.1093/carcin/9.3.365. [DOI] [PubMed] [Google Scholar]
- Marletta M. A. Nitric oxide synthase structure and mechanism. J Biol Chem. 1993 Jun 15;268(17):12231–12234. [PubMed] [Google Scholar]
- Miles A. M., Bohle D. S., Glassbrenner P. A., Hansert B., Wink D. A., Grisham M. B. Modulation of superoxide-dependent oxidation and hydroxylation reactions by nitric oxide. J Biol Chem. 1996 Jan 5;271(1):40–47. doi: 10.1074/jbc.271.1.40. [DOI] [PubMed] [Google Scholar]
- Moncada S., Palmer R. M., Higgs E. A. Nitric oxide: physiology, pathophysiology, and pharmacology. Pharmacol Rev. 1991 Jun;43(2):109–142. [PubMed] [Google Scholar]
- Pfeiffer S., Gorren A. C., Schmidt K., Werner E. R., Hansert B., Bohle D. S., Mayer B. Metabolic fate of peroxynitrite in aqueous solution. Reaction with nitric oxide and pH-dependent decomposition to nitrite and oxygen in a 2:1 stoichiometry. J Biol Chem. 1997 Feb 7;272(6):3465–3470. doi: 10.1074/jbc.272.6.3465. [DOI] [PubMed] [Google Scholar]
- Tamir S., Tannenbaum S. R. The role of nitric oxide (NO.) in the carcinogenic process. Biochim Biophys Acta. 1996 Oct 9;1288(2):F31–F36. doi: 10.1016/0304-419x(96)00021-2. [DOI] [PubMed] [Google Scholar]
- Uppu R. M., Squadrito G. L., Pryor W. A. Acceleration of peroxynitrite oxidations by carbon dioxide. Arch Biochem Biophys. 1996 Mar 15;327(2):335–343. doi: 10.1006/abbi.1996.0131. [DOI] [PubMed] [Google Scholar]
- Wood J., Garthwaite J. Models of the diffusional spread of nitric oxide: implications for neural nitric oxide signalling and its pharmacological properties. Neuropharmacology. 1994 Nov;33(11):1235–1244. doi: 10.1016/0028-3908(94)90022-1. [DOI] [PubMed] [Google Scholar]
- deRojas-Walker T., Tamir S., Ji H., Wishnok J. S., Tannenbaum S. R. Nitric oxide induces oxidative damage in addition to deamination in macrophage DNA. Chem Res Toxicol. 1995 Apr-May;8(3):473–477. doi: 10.1021/tx00045a020. [DOI] [PubMed] [Google Scholar]