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A Method for Estimating Contact Time of Red Cells in Lung Capillaries from O2 and CO2 Concentrations in Rebreathing Air in Man

  • M. Mochizuki
  • I. Shibuya
  • K. Uchida
  • T. Kagawa
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 215)

Abstract

In a previous paper (Mochizuki et al., 1986) we described the relation between alveolar- and venous-Pco2 and the contact time (tc). However, at that time, Pco2-dependency of the arterio-venous difference in O2 content ((a-v)Co2), the contact-time-dependency of the Haldane effect, and linearity of the relation between the experimental gas exchange ratio and Pco2 (R-Pco2 line) in rebreathing air were not taken into account. Recently, we have precisely analysed the above correlations from the numerical solutions of the simultaneous O2 and CO2 diffusions in the red blood cell (RBC). Based upon the results we have derived a corrected contact time equation. When the time constant of the reaction rate of the extracellular dehydration reaction was less than 0.2 sec, good agreement was observed between the contact time obtained from the pulmonary diffusing capacity for CO (Uchida, Shibuya and Mochizuki, 1986) and that from the present method.

Keywords

Time Constant Contact Time Dehydration Reaction Lung Capillary Pulmonary Diffuse Capacity 
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References

  1. Bidani, A., Mathew, S.J. and Crandall, E.D. (1983). Pulmonary vascular carbonic anhydrase activity. J. Appl. Physiol: Respir. Envir. Exercise Physiol. 55, 75–83.Google Scholar
  2. Klocke, R.A. (1978). Catalysis of CO2 reactions by lung carbonic anhydrase. J. Appl. Physiol. 44, 882–888.Google Scholar
  3. Mochizuki, M. and Kagawa, T. (1986) Numerical solution of partial differential equations describing the simultaneous O2 and CO2 diffusions in the red blood cell. Jpn. J. Physiol. 36, 43–63.CrossRefGoogle Scholar
  4. Mochizuki, M., Kagawa, T., Uchida, K. and Shibuya, I. (1986). Relation between the contact time and venous and alveolar Pco2 at rest. In: Oxygen Transport to Tissue-VIII. Ed. Longmuir, I.S., Plenum Press, New York and London, ( Adv. Exp. Med. Biol. 200, 27–34 ).Google Scholar
  5. Mochizuki, M. Tamura, M., Shimasaki, T., Niizeki, K. and Shimouchi, A. (1984). A new indirect method for measuring arteriovenous O2 content difference and cardiac output from O2 and CO2 concentrations by rebreathing air. Jpn. J. Physiol. 34, 295–306.CrossRefGoogle Scholar
  6. Shibuya, I., Uchida, K. and Mochizuki, M. (1987). Quantitative relations between gas exchange parameters including contact time at rest and during exercise. This volume.Google Scholar
  7. Tazawa, H., Mochizuki, M., Tamura, M., and Kagawa, T. (1983) Quantitative analyses of the CO2 dissociation curve of oxygenated blood and the Haldane effect in human blood. Jpn. J. Physiol. 33, 601–618.CrossRefGoogle Scholar
  8. Uchida, K., Shibuya, I. and Mochizuki, M. (1986). Simultaneous measurement of cardiac output and pulmonary diffusing capacity for CO by a rebreathing method. Jpn. J. Physiol. 36, 657–670.CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1987

Authors and Affiliations

  • M. Mochizuki
    • 1
  • I. Shibuya
    • 1
  • K. Uchida
    • 1
  • T. Kagawa
    • 1
  1. 1.Department of PhysiologyYamagata University School of MedicineYamagataJapan

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