Precapillary O2 Loss and Arteriovenous O2 Diffusion Shunt are Below Limit of Detection in Myocardium
Is venous PO2 an index of tissue PO2, of end capillary PO2, or neither of these because of diffusive shunting from arterioles to venules? To evaluate diffusive shunting and venous PO2 in myocardium we determined hemoglobin (Hb) saturation in arterioles and venules and myoglobin (Mb) saturation in individual subepicardial myocytes by use of a cryomicrospectrophotometric method (Gayeski, 1981, Degner and Gayeski, 1987).
KeywordsIntracellular Action Potential Venule Diameter Transmural Gradient Saturation Gradient Measuring Diaphragm
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- Degner, F., and Gayeski, T. E. J., 1987, A comparison of a four wavelength analysis and multicomponent wavelength analysis applied to determination of hemoglobin saturation, Adv. Exper. Med. Biol., 215:153.Google Scholar
- Gayeski, T. E. J., 1981, A Cryogenic Microspectrophotometric Method for Measuring Myoglobin Saturation in Subcellular Volumes; Application to Resting Dog Muscle, (Ph.D. Thesis), Rochester, NY: University of Rochester, Univ. Microfilms, No. DA9224720, Ann Arbor, MI.Google Scholar
- Gayeski, T. E. J., Federspiel, W. J., and Honig, C. R., 1988, A graphical analysis of the influence of red cell transit time, carrier-free layer thickness, and intracellular PO2 on blood-tissue O2 transport, Adv. Exper. Med. Biol., 222:25.Google Scholar
- Gayeski, T. E. J., and Honig, CR., 1986, O2 gradients from sarcolemma to cell interior in a red muscle at maximal VO2, Am. J. Physiol., 251:789.Google Scholar
- Gayeski, T. E. J., and Honig, C. R., 1988, Intracellular PO2 in individual cardiac myocytes in dog, cat, rabbit, ferret and rat, Am. J. Physiol., in press.Google Scholar
- Groebe, K., and Thews, G., 1986, Theoretical analysis of oxygen supply to contracted skeletal muscle, Adv. Exper. Med. Biol., 200:495.Google Scholar
- Harris, P. D., 1986, Movement of oxygen in skeletal muscle., News Phvsiol. Sci., 1:147.Google Scholar
- Honig, C. R., and Gayeski, T. E. J., 1987, Comparison of intracellular PO2 and conditions for blood-tissue O2 transport in heart and working red skeletal muscle, Adv. Exper. Med. Biol., 215:309.Google Scholar
- Kuo, L. and, Pittman, R. N., 1988, Effect of hemodilution on oxygen transport in arteriolar networks of hamster striated muscle, Am. J. Phvsiol., 254:H331.Google Scholar
- Pittman, R. N., and Duling, B. R., 1977, The determination of oxygen availability in the microcirculation, in: “Oxygen and Physiological Function.” F.F. Jöbsis, ed., Prof. Infor. Library, Dallas, Texas.Google Scholar
- Schubert, R. W., Whalen, W. J., and Nair, P., 1978, Myocardial PO2 distribution: Relationship to coronary autoregulation, Am. J. Phvsiol., 234:H361.Google Scholar
- Whalen, W. J., Nair, P., and Buerk, D., 1973, O2 tension in the beating cat heart in situ, in: “O2 Supply.” M. Kessler, D. F. Bruley, L. C. Clark, Jr., D. W. Lübbers, I. K. Silver, and J. Strauss, eds., University Park Press, Baltimore, Maryland.Google Scholar