title: Cerebral formation of free radicals during hypoxia does not cause structural damage and is associated with a reduction in mitochondrial PO2; evidence of O2-sensing in humans?
abstract: Cellular hypoxia triggers a homeostatic increase in mitochondrial free radical signaling. In this study, blood was obtained from the radial artery and jugular venous bulb in 10 men during normoxia and 9  hours hypoxia (12.9% O(2)). Mitochondrial oxygen tension (p(O(2))(mit)) was derived from cerebral blood flow and blood gases. The ascorbate radical (A(•-)) was detected by electron paramagnetic resonance spectroscopy and neuron-specific enolase (NSE), a biomarker of neuronal injury, by enzyme-linked immunosorbent assay. Hypoxia increased the cerebral output of A(•-) in proportion to the reduction in p(O(2))(mit), but did not affect NSE exchange. These findings suggest that neuro-oxidative stress may constitute an adaptive response.
authors.affiliation: Neurovascular Research Laboratory, Faculty of Health, Science and Sport, University of Glamorgan, Glamorgan, UK. dbailey1@glam.ac.uk
authors.forename: Damian M
authors.initials: DM
authors.lastname: Bailey
authors.forename: Sarah
authors.initials: S
authors.lastname: Taudorf
authors.forename: Ronan M G
authors.initials: RM
authors.lastname: Berg
authors.forename: Carsten
authors.initials: C
authors.lastname: Lundby
authors.forename: Bente K
authors.initials: BK
authors.lastname: Pedersen
authors.forename: Peter
authors.initials: P
authors.lastname: Rasmussen
authors.forename: Kirsten
authors.initials: K
authors.lastname: Møller
mesh_terms: D000328:Adult; D001205:Ascorbic Acid / Q000378:metabolism; D001784:Blood Gas Analysis; D001923:Brain Chemistry; D002560:Cerebrovascular Circulation / Q000502:physiology; D005609:Free Radicals / Q000378:metabolism*; D006261:Headache / Q000209:etiology; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D002534:Hypoxia, Brain / Q000378:metabolism* / Q000473:pathology; D007700:Kinetics; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D010751:Phosphopyruvate Hydratase / Q000378:metabolism
chemical_list: D005609:Free Radicals; D010751:Phosphopyruvate Hydratase; D001205:Ascorbic Acid; D010100:Oxygen