The Pathways of Oxygen in Brain I

Delivery and metabolism of oxygen
  • Albert Gjedde
Conference paper
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 566)


Flow-metabolism coupling in brain is different from flow-metabolism coupling in other vascular beds. In the classic description of Krogh1, the capillary bed is a system of parallel tubes serving cylinders of tissue known as Krogh’s cylinders. This simple arrangement yielded a quantitative expression of oxygen delivery to the tissue. However, in brain tissue, the arrangement is so disorderly that no prediction of oxygen tensions in the tissue is possible2.

Only two claims of the capillary bed in the brain appear to be indisputable, i.e., the capillaries have a common arterial source and a common venous terminus, and their density is proportional to the average regional rates of metabolism at steady-state. The following revision of the mechanism of flow-metabolism coupling in brain arose from the simple assumption, first introduced by Erwin R. Weibel in The Pathway for Oxygen,3 that every segment of the capillary bed “feeds” the same amount of brain tissue, i.e., that every fraction of the tissue is served by commensurate fractions of capillary density and oxygen diffusibility and accounts for the same fraction of the total oxygen consumption.


Oxygen Tension Oxygen Diffusibility Arterial Oxygen Tension Oxygen Extraction Fraction Cortical Blood Flow 
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  1. 1.
    A. Krogh, The number and distribution of capillaries in muscles with calculations of the oxygen pressure head necessary for supplying the tissue, J. Physiol. 52, 405–415 (1919).Google Scholar
  2. 2.
    C. Y. Wang, and J. Bassingthwaighte, Capillary supply regions, Math. Biosci. 173, 103–114 (2001).PubMedCrossRefGoogle Scholar
  3. 3.
    E. R. Weibel, The Pathway for Oxygen (Harvard University Press, Cambridge, 1984).Google Scholar
  4. 4.
    A. Gjedde, Cerebral blood flow change in arterial hypoxemia is consistent with negligible oxygen tension in brain mitochondria, NeuroImage 17, 1876–1881 (2002).PubMedCrossRefGoogle Scholar
  5. 5.
    M. S. Vafaee, and A. Gjedde, Model of bloodbrain transfer of oxygen explains nonlinear flow metabolism coupling during stimulation of visual cortex, J. Cereb. Blood Flow Metab. 20, 747–754 (2000).PubMedCrossRefGoogle Scholar
  6. 6.
    E. Gnaiger, R. Steinlechner-Maran, G. Mendez, T. Eberl, and R. Margreiter, Control of mitochondrial and cellular respiration by oxygen, J. Bioenerg. Biomembr. 27, 583–596 (1995).PubMedCrossRefGoogle Scholar
  7. 7.
    E. Gnaiger, B. Lassnig, A. Kuznetsov, G. Rieger, and R. Margreiter, Mitochondrial oxygen affinity, respiratory flux control and excess capacity of cytochrome c oxidase, J. Exp. Biol. 201, 1129–1139 (1998).PubMedGoogle Scholar
  8. 8.
    C. Guilivi, Functional implications of nitric oxide produced by mitochondria in mitochondrial metabolism, Biochem. J. 332, 673–679 (1998).Google Scholar
  9. 9.
    M. S. Vafaee, E. Meyer, S. Marrett, T. Paus, A. C. Evans, and A. Gjedde, Frequencydependent changes in cerebral metabolic rate of oxygen during activation of human visual cortex, J. Cereb. Blood Flow Metab. 19, 272–277 (1999).PubMedCrossRefGoogle Scholar
  10. 10.
    A. Gjedde, S. Marrett, M. Sakoh, and M. Vafaee, Model of oxygen delivery to brain tissue in vivo explains beneficial effect of hypothermia in ischemia, in: Brain Activation and CBF Control, edited by M. Tomita, I. Kanno, and E. Hamel (Elsevier, Tokyo, 2002), pp. 223–229.Google Scholar
  11. 11.
    A. Kastrup, G. Kruger, T. Neumann-Haefelin, G. H. Glover, and M. E. Moseley, Changes of cerebral blood flow, oxygenation, and oxidative metabolism during graded motor activation, NeuroImage 15, 74–82 (2002).PubMedCrossRefGoogle Scholar
  12. 12.
    M. Sakoh, and A. Gjedde, Neuroprotection in hypothermia linked to redistribution of oxygen in brain, Am. J. Physiol. 285, H17–H25 (2003).Google Scholar
  13. 13.
    A. Gjedde, and S. Marrett, Glycolysis in neurons, not astrocytes, delays oxidative metabolism of human visual cortex during sustained checkerboard stimulation in vivo, J. Cereb. Blood Flow Metab. 21, 1384–1392 (2001).PubMedCrossRefGoogle Scholar

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© Springer Science+Business Media, Inc. 2005

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  • Albert Gjedde

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