• myGriffith
    • Staff portal
    • Contact Us⌄
      • Future student enquiries 1800 677 728
      • Current student enquiries 1800 154 055
      • International enquiries +61 7 3735 6425
      • General enquiries 07 3735 7111
      • Online enquiries
      • Staff phonebook
    View Item 
    •   Home
    • Griffith Research Online
    • Journal articles
    • View Item
    • Home
    • Griffith Research Online
    • Journal articles
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

  • All of Griffith Research Online
    • Communities & Collections
    • Authors
    • By Issue Date
    • Titles
  • This Collection
    • Authors
    • By Issue Date
    • Titles
  • Statistics

  • Most Popular Items
  • Statistics by Country
  • Most Popular Authors
  • Support

  • Contact us
  • FAQs
  • Admin login

  • Login
  • Gray matter blood flow change is unevenly distributed during moderate isocapnic hypoxia in humans

    Author(s)
    Binks, Andrew P
    Cunningham, Vincent J
    Adams, Lewis
    Banzett, Robert B
    Griffith University Author(s)
    Adams, Lewis
    Year published
    2008
    Metadata
    Show full item record
    Abstract
    Hypoxia increases cerebral blood flow (CBF), but it is unknown whether this increase is uniform across all brain regions. We used H215O positron emission tomography imaging to measure absolute blood flow in 50 regions of interest across the human brain (n = 5) during normoxia and moderate hypoxia. PCO2 was kept constant (44 Torr) throughout the study to avoid decreases in CBF associated with the hypocapnia that normally occurs with hypoxia. Breathing was controlled by mechanical ventilation. During hypoxia (inspired PO2 = 70 Torr), mean end-tidal PO2 fell to 45 ᠶ.3 Torr (means ᠓D). Mean global CBF increased from normoxic ...
    View more >
    Hypoxia increases cerebral blood flow (CBF), but it is unknown whether this increase is uniform across all brain regions. We used H215O positron emission tomography imaging to measure absolute blood flow in 50 regions of interest across the human brain (n = 5) during normoxia and moderate hypoxia. PCO2 was kept constant (44 Torr) throughout the study to avoid decreases in CBF associated with the hypocapnia that normally occurs with hypoxia. Breathing was controlled by mechanical ventilation. During hypoxia (inspired PO2 = 70 Torr), mean end-tidal PO2 fell to 45 ᠶ.3 Torr (means ᠓D). Mean global CBF increased from normoxic levels of 0.39 ᠰ.13 to 0.45 ᠰ.13 ml/g during hypoxia. Increases in regional CBF were not uniform and ranged from 9.9 ᠸ.6% in the occipital lobe to 28.9 ᠱ0.3% in the nucleus accumbens. Regions of interest that were better perfused during normoxia generally showed a greater regional CBF response. Phylogenetically older regions of the brain tended to show larger vascular responses to hypoxia than evolutionary younger regions, e.g., the putamen, brain stem, thalamus, caudate nucleus, nucleus accumbens, and pallidum received greater than average increases in blood flow, while cortical regions generally received below average increases. The heterogeneous blood flow distribution during hypoxia may serve to protect regions of the brain with essential homeostatic roles. This may be relevant to conditions such as altitude, breath-hold diving, and obstructive sleep apnea, and may have implications for functional brain imaging studies that involve hypoxia.
    View less >
    Journal Title
    Journal of Applied Physiology
    Volume
    104
    Issue
    1
    DOI
    https://doi.org/10.1152/japplphysiol.00069.2007
    Copyright Statement
    Self-archiving of the author-manuscript version is not yet supported by this journal. Please refer to the journal link for access to the definitive, published version or contact the author[s] for more information.
    Subject
    Biological sciences
    Biomedical and clinical sciences
    Medical physiology not elsewhere classified
    Publication URI
    http://hdl.handle.net/10072/23274
    Collection
    • Journal articles

    Footer

    Disclaimer

    • Privacy policy
    • Copyright matters
    • CRICOS Provider - 00233E
    • TEQSA: PRV12076

    Tagline

    • Gold Coast
    • Logan
    • Brisbane - Queensland, Australia
    First Peoples of Australia
    • Aboriginal
    • Torres Strait Islander