title: In vivo on-line detection of no distribution in endotoxin-treated mice by l-band ESR.
abstract: The report describes a method for tracing nitric oxide (NO) distribution in endotoxin-treated mice using in vivo low-frequency L-band (1.1 GHz) electron spin resonance spectroscopy (ESR) in combination with extracellular nitric oxide trapping complex consisting of N-methyl-D-glucamine dithiocarbamate and iron (MGD-Fe). An ESR signal characteristic of the MGD-Fe-NO complex was found in the upper abdomen (liver region), lower abdomen and head region of ICR mice. The origin of NO from the L-arginine-NO synthase (NOS) pathway was confirmed using the NOS inhibitor N(G)-monomethyl-L-arginine (NMMA) and isotopic tracing experiments with 15N-labelled L-arginine. Experiments with mice lacking inducible NOS (iNOS) and matched wild type animals were performed using the NO trapping agent diethyldithiocarbamate (DETC). These experiments demonstrated that endotoxin-induced NO generation in the liver tissue of mice occurs via the iNOS isoform of NOS. The described in vivo ESR technique using a "whole body" resonator allows in vivo on-line detection of endogenous NO in mice.
authors.affiliation: Department of Physiology and Experimental Medicine, The George Washington University Medical Center, Washington, DC 20037, USA. amkoma@gwis2.circ.gwu.edu
authors.forename: A M
authors.initials: AM
authors.lastname: Komarov
mesh_terms: D000818:Animals; D001120:Arginine / Q000378:metabolism; D002614:Chelating Agents / Q000494:pharmacology; D004050:Ditiocarb / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D004731:Endotoxins / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D008954:Models, Biological; D009569:Nitric Oxide / Q000032:analysis*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D020033:Protein Isoforms; D013012:Sorbitol / Q000031:analogs & derivatives* / Q000494:pharmacology; D013113:Spin Labels; D013859:Thiocarbamates / Q000494:pharmacology; D013997:Time Factors; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D002614:Chelating Agents; D004731:Endotoxins; D004791:Enzyme Inhibitors; D020033:Protein Isoforms; D013113:Spin Labels; D013859:Thiocarbamates; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D013012:Sorbitol; C041262:N-methyl-D-glucamine dithiocarbamate; D001120:Arginine; D004050:Ditiocarb; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse