Nitric oxide: prospects and perspectives of in vivo detection by L-band EPR spectroscopy.
This paper discusses, compares and evaluates various in vivo EPR methods of detection of nitric oxide (NO). In particular the various classes of agents are: Fe(II)-dithiocarbamate derivative complexes of MGD (N-methyl-D-glucamine dithiocarbamate) and DTCS [N-(dithiocarboxy)sarcosine], stable imidazolineoxy N-oxides and nitronyl N-oxides, and NO-sensitive chars. As a specific example direct, real-time, in vivo measurements of nitric oxide (NO) in mice are described with the water soluble metal chelator complex (MGD)2-Fe(II), as monitored at L-band EPR. The three-line EPR spectrum of [(MGD)2-Fe(II)-NO] was observed non-invasively in both control animals injected with the preformed product [(MGD)2-Fe(II)-NO] and from lipopolysaccharide (LPS) treated mice subsequently injected with (MGD)2-Fe(II) complex. The [(MGD)2-Fe(II)-NO] spectrum was markedly suppressed after administration of phenyl N-tert-butyl nitrone (PBN) prior to LPS injection as PBN inhibits the expression of inducible nitric oxide synthase (iNOS). When 15N-arginine was administered to LPS-treated mice, an EPR spectrum consisting of both three- and two-line EPR signals (due to (MGD)2-Fe(II)-14NO and (MGD)2-Fe(II)-15NO respectively) was observed, confirming that the trapped NO was generated through the NOS enzyme and not other chemical routes.
Department of Inflammation Research, Tokyo Metropolitan Institute of Medical Science, Rinshoken, Japan.
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Fujii
L J
LJ
Berliner
D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005069:Evaluation Studies as Topic; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D013113:Spin Labels
D013113:Spin Labels; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase