title: Mechanisms of free radical chemistry and biochemistry of benzene.
abstract: omicron-Tyrosine (omicron-Tyr) was used as a specific biomarker for .OH radicals generated in biosystems. Specificity of omicron-Tyr as an .OH biomarker was based on previous studies in systems exposed to ionizing radiations. Fresh muscle tissue incubated with benzene for 1 hr at 38 degrees C exhibits formation of omicron-Tyr as seen in the cases of ethanol- and carbon tetrachloride-exposed systems. Gas chromatography/mass spectrometry selective ion monitoring measurements of omicron-Tyr yields in chicken breast muscle incubated with water or benzene indicate levels of less than 0.1 ppm and 3.0 +/- 0.5 ppm of omicron-Tyr, respectively. Formation of .OH is presumed to originate via a Haber-Weiss reaction of H2O2 with Fe(II) preceded by the formation of .O2- and H2O2 from distorted mitochondria.
authors.affiliation: Center for Radiation Research, National Bureau of Standards, Gaithersburg, MD 20899.
authors.forename: L R
authors.initials: LR
authors.lastname: Karam
authors.forename: M G
authors.initials: MG
authors.lastname: Simic
mesh_terms: D000818:Animals; D001554:Benzene / Q000378:metabolism* / Q000633:toxicity; D002645:Chickens; D005609:Free Radicals; D008401:Gas Chromatography-Mass Spectrometry; D006861:Hydrogen Peroxide / Q000378:metabolism; D006878:Hydroxides / Q000378:metabolism; D017665:Hydroxyl Radical; D066298:In Vitro Techniques; D008956:Models, Chemical; D009132:Muscles / Q000187:drug effects* / Q000378:metabolism; D014443:Tyrosine / Q000032:analysis
chemical_list: D005609:Free Radicals; D006878:Hydroxides; D017665:Hydroxyl Radical; D014443:Tyrosine; C026741:2-tyrosine; D006861:Hydrogen Peroxide; D001554:Benzene