Advertisement

Improved O2 Transfer to Tissues During Deep Hypoxia in Rats with a Left-Shifted Blood O2 Dissociation Curve

  • Z. Turek
  • F. Kreuzer
  • B. E. M. Ringnalda
  • P. Scotto
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 169)

Abstract

Oxygen is transported in blood while bound to a highly specialized carrier, the hemoglobin in the red cells. The loading of hemoglobin with O2 in the lung depends on the partial pressure of O2 in the alveolar air. During hypoxic hypoxia this pressure remains lowered in spite of hyperventilation, so that if the total transfer of O2 from the lung to tissues is to be guaranteed, either the loading of blood with O2 in the lung must be enhanced, or blood flow through the lung or O2 extraction in tissues must increase. It is well known that the extraction of O2 from blood has its limits which are different in different organs. During hypoxic hypoxia, an increase of the loading ability of blood in the lung or of blood flow through the lung is required to compensate for the decrease of Po2 in the alveolar air. The loading ability of blood can be enhanced by an increase of blood O2 carrying capacity accompanied by polycythemia, or by an increase of blood O2 affinity, i.e., a shift of the blood O2 dissociation curve (ODC) to the left. The former is the usual reaction of many mammalian species to chronic hypoxia, with the potential danger that excessive polycythemia may increase blood viscosity to such a degree that flow may become limited. An increase of blood O2 affinity improves the loading in the lung but impairs the unloading in tissues.

Keywords

Dissociation Curve Severe Hypoxia Alveolar Ventilation Capacitance Coefficient Hypoxic Hypoxia 
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. Bakker, J.D., Gortmaker, G.C., Vrolijk, A.D.M., and Offerijns, F.J.G., 1976, The influence of the position of the oxygen dissociation curve on oxygen-dependent functions of the isolated perfused rat liver. I. Studies at different levels of hypoxic hypoxia, Pflügers Arch., 362: 21–31.PubMedCrossRefGoogle Scholar
  2. Eaton, J.W., Skelton, T.D., and Berger, E., 1974, Survival at extreme altitude: protective effect of increased hemoglobin-oxygen affinity, Science, 183: 743–744.PubMedCrossRefGoogle Scholar
  3. Frans, A., Turek, Z., Yokota, H., and Kreuzer, F., 1979, Effect of variations in blood hydrogen ion concentration on pulmonary gas exchange of artificially ventilated dogs, Pflügers Arch., 380: 35–39.PubMedCrossRefGoogle Scholar
  4. Kreuzer, F., 1967, Transport of O2 and CO2 at altitude, in: “Exercise at Altitude”, R. Margaria, ed., Excerpta Medica Foundation, Amsterdam.Google Scholar
  5. Monge, C, and Whittembury, J., 1976, High altitude adaptations in the whole animal, in: “Environmental Physiology of Animals”, J. Bligh, J.L. Cloudsley-Thompson, A.G. Macdonald, eds., Black-well Scientific Publications, Oxford.Google Scholar
  6. Penney, D., and Thomas, M., 1975, Hematological alterations and response to acute hypobaric stress, J. Appl. Physiol., 39: 1034–1037.PubMedGoogle Scholar
  7. Piiper, J., Dejour, P., Haab, P., and Rahn, H., 1971, Concepts and basic quantities in gas exchange physiology, Respir. Physiol., 13: 292–304.PubMedCrossRefGoogle Scholar
  8. Roughton, F.J.W., and Scholander, P.F., 1943, Micro gasometric estimation of the blood gases. I. Oxygen, J. Biol. Chem., 148: 541–550.Google Scholar
  9. Samaja, M., Veicsteinas, A., and Cerretelli, P., 1979, Oxygen affinity of blood in altitude Sherpas, J. Appl. Physiol.: Respir. Environ. Exercise Physiol., 47: 337–341.Google Scholar
  10. Scotto, P., Turek, Z., Licheri, D., and Ringnalda, B.E.M., 1981, Blood O2 dissociation curve and O2 transport to the isolated and perfused turtle heart, in: “Oxygen Transport to Tissue”, Adv. Physiol. Sci. Vol. 25, A.G.B. Kovách, E. Dóra, M. Kessler, I.A. Silver, eds., Pergamon Press, Akadémiai Kiadó, Budapest.Google Scholar
  11. Turek, Z., and Kreuzer, F., 1976, Effect of a shift of the oxygen dissociation curve on myocardial oxygenation at hypoxia, in: “Okygen Transport to Tissue II”, Adv. Exp. Med. Biol., Vol. 75, J. Grote, D. Reneau, G. Thews, eds., Plenum Press, New York-London.Google Scholar
  12. Turek, Z., and Kreuzer, F., 1981, Effect of shifts of the O2 dissociation curve upon alveolar-arterial O2 gradients in computer models of the lung with ventilation-perfusion mismatching, Respir. Physiol., 45: 133–139.PubMedCrossRefGoogle Scholar
  13. Turek, Z., Kreuzer, F., and Hoofd, L.J.C., 1973, Advantage or disadvantage of a decrease of blood oxygen affinity for tissue oxygen supply at hypoxia, Pflügers Arch., 342: 185–197.PubMedCrossRefGoogle Scholar
  14. Turek, Z., Kreuzer, F., and Ringnalda, B.E.M., 1978a, Blood gases at several levels of oxygenation in rats with a left-shifted blood oxygen dissociation curve, Pflügers Arch., 376: 7–13.PubMedCrossRefGoogle Scholar
  15. Turek, Z., Kreuzer, F., Turek-Maischeider, M., and Ringnalda, B.E.M., 1978b, Blood O2 content, cardiac output, and flow to organs at several levels of oxygenation in rats with a left-shifted blood oxygen dissociation curve, Pflügers Arch., 376: 201–207.PubMedCrossRefGoogle Scholar
  16. Woodson, R.D., Wranne, B., and Detter, J.C., 1973, Effect of increased blood oxygen affinity on work performance of rats, J. Clin. Invest., 52: 2717–2714.PubMedCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1984

Authors and Affiliations

  • Z. Turek
    • 1
  • F. Kreuzer
    • 1
  • B. E. M. Ringnalda
    • 2
  • P. Scotto
    • 2
  1. 1.Dept. of PhysiologyUniv. of NijmegenNijmegenThe Netherlands
  2. 2.Dept. of Human PhysiologyUniv. of NaplesNaplesItaly

Personalised recommendations