Advertisement

Subcellular Control of Oxygen Transport

  • E. Takahashi
  • K. Doi
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 393)

Abstract

According to the Fick’s law of diffusion, oxygen pressure of mitochondrial inner membrane (PMt) is defined by the following equation;
$${P_{Mt}} = {P_{cap}} - {\dot V_{{O_2}}} \cdot R,$$
where Pcap, \({\dot V_{{O_2}}}\),and R denote Po2 of capillary blood, flux of oxygen into mitochondria (oxygen consumption rate of the cell), and diffusion resistance of tissue, respectively. R is a lumped parameter and includes diffusion resistance of plasma, capillary wall, extracellular fluid, plasma membrane, cytosol, and mitochondrial inner membrane. Therefore, the oxygen pressure gradient between capillary blood and mitochondria is represented by \({\dot V_{{O_2}}} \cdot R\). Magnitude of the oxygen pressure gradient in vivo appears so large (> 20–25 Torr) that intracellular (cytosolic) Po2 of normal beating heart may be around P50 of myoglobin, i.e., ~3 Torr (11). Furthermore, additional oxygen pressure gradients between cytosol and mitochondrial inner membrane result in quite low Po2at mitochondrial enzymes.

Keywords

Oxygen Transport Oxygen Consumption Rate Oxygen Flux Simulated Ischaemia HEPES Buffer Solution 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Clark, A., JR., P. A. A. Clark, R. J. Connett, T. E. J. Gayeski, and C. R. Honig. How large is the drop in Po2 between cytosol and mitochondria? Am. J. Physiol. 252:C583–C687, 1987.PubMedGoogle Scholar
  2. 2.
    Coburn, R. F., F. Ploegmakers, P. Gondrie, and R. Abboud. Myocardial myoglobin oxygen tension. Am. Physiol. 224:870–876, 1973.Google Scholar
  3. 3.
    Gayeski, T. E. J. and C. R. Honig. Intracellular Po2 in individual cardiac myocytes in dogs, cats, rabbits, ferrets, and rats. Am. J. Physiol. 260:H522–H531, 1991.PubMedGoogle Scholar
  4. 4.
    Honig, C. R. and T. E. J. Gayeski. Resistance of O2 diffusion in anemic red muscle: roles of flux density and cell Po2. Am. J. Physiol. 265:H868–H875, 1993.PubMedGoogle Scholar
  5. 5.
    Kennedy, F. G. and D. P. Jones. Oxygen dependence of mitochondrial function in isolated rat cardiac myocytes. Am. J Physiol. 250:C374–C383, 1986.PubMedGoogle Scholar
  6. 6.
    Kreutzer, U. and T. Jue. 1H-nuclear magnetic resonance deoxymyoglobin signal as indicator of intracel-lular oxygenation in myocardium. Am. J. Physiol. 261:H2091–H2097, 1991.PubMedGoogle Scholar
  7. 7.
    Snow, T. R. and H. L. Stone. A study of factors affecting the oxidation-reduction state of cyt a,a3 in the in-situ canine heart. J. Appl. Cardiol. 3:191–196, 1988.Google Scholar
  8. 8.
    Tamura, M., N. Oshino, B. Chance, and I. A. Silver. Optical measurements of intracellular oxygen concentration of rat heart in vitro. Arch. Biochem. Biophys. 191:8–22, 1978.CrossRefGoogle Scholar
  9. 9.
    Takahashi, E. and K. Doi. Digital imaging of the oxygenation state within an isolated single rat cardiomyocyte. Adv. Exp. Med. Biol. 361: 163–169, 1994.PubMedCrossRefGoogle Scholar
  10. 10.
    Wittenberg, B. A. and J. B. Wittenberg. Oxygen pressure gradients in isolated cardiac myocytes. J. Biol. Chem. 260:6548–6554, 1985.PubMedGoogle Scholar
  11. 11.
    Wittenberg, B. A. and J. B. Wittenberg. Transport of oxygen in muscle. Annu. Rev. Physiol., 51:857–878, 1989.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1995

Authors and Affiliations

  • E. Takahashi
    • 1
  • K. Doi
    • 1
  1. 1.Department of PhysiologyYamagata University School of MedicineYamagataJapan

Personalised recommendations