title: An electron paramagnetic resonance investigation of the oxygen dependence of the arterial-venous gradient of nitrosyl hemoglobin in blood circulation.
abstract: Whether there is a nitrosyl hemoglobin (HbNO) gradient between the venous and the arterial parts of the circulatory system is a very controversial issue in nitric oxide research. We have carefully evaluated the measurement of HbNO concentration in blood using EPR generated in vivo by the NO donor DEANO under various oxygen tensions. We found that the absolute concentrations of HbNO in venous and arterial blood were the same within experimental error, independent of hemoglobin saturation; only the ratios of 5-coordinate and 6-coordinate HbNO differed. The HbNO concentration increased when the oxygen concentration breathed by the rats decreased in a manner that was linear in hemoglobin saturation. These results do not support the existence of an arterial-venous gradient of HbNO under our experimental conditions.
authors.affiliation: Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA. jiang1@niehs.nih.gov
authors.forename: JinJie
authors.initials: J
authors.lastname: Jiang
authors.forename: Jean
authors.initials: J
authors.lastname: Corbett
authors.forename: Neil
authors.initials: N
authors.lastname: Hogg
authors.forename: Ronald P
authors.initials: RP
authors.lastname: Mason
mesh_terms: D000818:Animals; D001158:Arteries / Q000502:physiology; D004578:Electron Spin Resonance Spectroscopy; D006454:Hemoglobins / Q000378:metabolism*; D006834:Hydrazines / Q000494:pharmacology; D008297:Male; D010100:Oxygen / Q000097:blood*; D010313:Partial Pressure; D051381:Rats; D014680:Veins / Q000502:physiology
chemical_list: D006454:Hemoglobins; D006834:Hydrazines; C008657:nitrosyl hemoglobin; C084012:1,1-diethyl-2-hydroxy-2-nitrosohydrazine; D010100:Oxygen