Cerebral Bioenergetics and in Vivo Cytochrome c Oxidase Redox Relationships

  • A. L. Sylvia
  • C. A. Piantadosi
  • F. F. Jöbsis-Vander Vliet
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 191)


Cytochrome c oxidase (cytochrome a,a3) is almost completely oxidized in isolated mitochondria1 which essentially respire at a maximal rate. The reduction level of cytochrome a,a 3 measured in intact brain and other mammalian organs, however, is much higher2,3. The in vivo oxidation-reduction level of this enzyme is also greatly affected by variations in tissue oxygenation4. Cytochrome a,a 3 becomes progressively more reduced by pathophysiological conditions which decrease cellular oxygen availability5. Thus, in situ changes in the oxidation level of cytochrome a,a 3 should provide an early sensitive means for determining intracellular levels of oxygen insufficiency which adversely affect tissue bioenergetics. We test this possibility in the present study. The effect of acute oxygen insufficiency on in stu changes in the oxidation level of cytochrome a,a 3 in the parietal cortex of skull intact normal blood circulated rat brain was directly compared with in vitro measured changes in the concentration of metabolites known to reflect limitations in cellular energy production.


Parietal Cortex Inspire Oxygen Oxidation Level Fractional Content Hemoglobin Saturation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Chance, B. and Williams, G.R. Respiratory enzymes in oxidative phosphorylation. III. The steady state. J. Biol. Chem. 217:409–427, 1955PubMedGoogle Scholar
  2. 2.
    Jöbsis, F.F. and LaManna, J.C. Kinetic aspects of intracellular redox reactions. In Extrapulmonary Manifestations of Respiratory Disease, Marcel Dekker, New York, N.Y., pp. 63–108, 1978Google Scholar
  3. 3.
    Snow, T.R., Kleinman, L.H., LaManna, J.C., Wechsler, A.S. and Jobsis, F.F. Response of cyt a, a 3 in the in situ canine heart to transient ischemic episodes. Basic Res. Cardiol. 76:289–304, 1981PubMedCrossRefGoogle Scholar
  4. 4.
    Rosenthal, M., LaManna, J.C., Jobsis, F.F., Levasseur, J.E., Kontos, H.A. and Patterson, J.L. Effects of respiratory gases on cytochrome a in intact cerebral cortex: Is there a critical PO2? Brain Res. 108:143–154, 1976PubMedCrossRefGoogle Scholar
  5. 5.
    Sylvia, A.L. and Rosenthal, M. The effect of age and lung pathology on cytochrome a,a 3 redox levels in the rat cerebral cortex. Brain Res. 146:109–122, 1978PubMedCrossRefGoogle Scholar
  6. 6.
    Jobsis, F.F., Keizer, J.H., LaManna, J.C. and Rosenthal, M. Reflectance spectrophotometry of cytochrome a,a3 in vivo. J. appl. Physiol. 43:858–872, 1977PubMedGoogle Scholar
  7. 7.
    Pontén, U., Ratcherson, R.A., Salford, L.G. and Siesjö, B.K. Optimal freezing conditions for cerebral metabolites in rats. J. Neurochem. 21:1127–1138, 1973PubMedCrossRefGoogle Scholar
  8. 8.
    Lowry, O.H. and Passonneau, J.V. A Flexible System of Enzymatic Analysis, New York: Academic Press, 1972Google Scholar

Copyright information

© Plenum Press, New York 1985

Authors and Affiliations

  • A. L. Sylvia
    • 1
  • C. A. Piantadosi
    • 1
  • F. F. Jöbsis-Vander Vliet
    • 1
  1. 1.Department of Physiology and MedicineDuke University Medical CenterDurhamUSA

Personalised recommendations