title: Measurements of pertinent concentrations of oxygen in vivo.
abstract: A new method able to measure the concentration of oxygen in complex biological systems, including in vivo, has been developed using low-frequency EPR and newly characterized free radicals that are very sensitive to the concentration of oxygen. The free radicals (fusinite and lithium phthalocyanine) are very stable in tissues (for at least 150 days), apparently nontoxic, and can reflect oxygen concentrations that are less than the Km of cytochrome oxidase (0.1 microM or lower). Their biological stability is indicated by the fact that repeated measurements with fusinite of the concentration of oxygen in skeletal muscle have been made in the same animal for more than 150 days without any change in sensitivity or signs of toxicity.
authors.affiliation: University of Illinois, Department of Physiology and Biophysics, Urbana 61801.
authors.forename: H M
authors.initials: HM
authors.lastname: Swartz
authors.forename: S
authors.initials: S
authors.lastname: Boyer
authors.forename: P
authors.initials: P
authors.lastname: Gast
authors.forename: J F
authors.initials: JF
authors.lastname: Glockner
authors.forename: H
authors.initials: H
authors.lastname: Hu
authors.forename: K J
authors.initials: KJ
authors.lastname: Liu
authors.forename: M
authors.initials: M
authors.lastname: Moussavi
authors.forename: S W
authors.initials: SW
authors.lastname: Norby
authors.forename: N
authors.initials: N
authors.lastname: Vahidi
authors.forename: T
authors.initials: T
authors.lastname: Walczak
mesh_terms: D000818:Animals; D003031:Coal; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D007211:Indoles; D054833:Isoindoles; D051379:Mice; D010100:Oxygen / Q000032:analysis*; D051381:Rats
chemical_list: D003031:Coal; D005609:Free Radicals; D007211:Indoles; D054833:Isoindoles; D010100:Oxygen; C013647:phthalocyanine