The Oxygen Dependence of Cellular Energy Metabolism
It is well known that supply of oxygen to the heart is equal to the rate of oxygen utilization over a wide range of physical work loads (see Eckenhoff et al., 1947; Alella et al., 1955; Neely et al., 1967; Nuutinen et al., 1982). This precise regulation of oxygen delivery is expressed in the fact that the arterial venous difference in oxygen tension remains essentially constant when the heart work rates increase from minimal to near maximal levels. However, such precise regulation requires a tissue “oxygen sensor” i.e. an oxygen dependent metabolic system which detects changes in tissue oxygen tension in the physiological range and transduces this information into a form which regulates vascular resistance. In the present communication we will summarize data which indicate that the oxygen sensor for regulation of coronary flow is mitochondrial oxidative phosphorylation. We will then demonstrate that this metabolic pathway is oxygen sensitive in the physiological range of oxygen tensions both in vivo and in vitro and thus fulfills the requirements for the tissue “oxygen sensor”.
KeywordsOxygen Tension Coronary Flow Oxygen Sensor Mitochondrial Oxidative Phosphorylation Tissue Oxygen Tension
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- Alella, A., Williams, F.L., Bolene-Williams, C. and Katz, L.N., 1955, Interrelation between cardiac oxygen consumption and coronary blood flow, Am. J. Physiol., 183: 570–582.Google Scholar
- Erecidska, M., Wilson, D.F. and Nishiki, K., 1978, Homeostatic regulation of cellular energy metabolism: Experimental characterization in vivo and fit to a model., Amer. J. Physiol., 234: C82 - C89.Google Scholar
- Kashiwagura, T., Wilson, D.F. and Erecidska, M., 1984, Oxygen dependence of cellular metabolism: The effect of 02 tension on gluconeogenesis and urea synthesis in isolated rat hepatocytes, J. Cell. Physiol. in Press.Google Scholar
- Longmuir, I.S., 1957, Respiration rate of rat liver cells at low oxygen concentrations, Biochem. J. 65: 378–382.Google Scholar
- Peterson, L.C., Nicholls, P. and Degn, H., 1974, The effect of energization on the apparent Michaelis-Menten constant for oxygen in mitochondrial respiration, Biochem.J. 142: 249–252.Google Scholar
- Reyes, J.G., Erdmann, W., Mardis, M., Karp, R.B., King, M. and Lell, W.A., 1978, Evidence for existence of intramyocardial steal, in “Oxygen transport to Tissue III”, I.A. Silver, M. Erecidska and H. Bicher eds. Plenum, New York, p. 755–760.Google Scholar
- Sugano, T., Oshino, N.and Chance, B., 1974, Mitochondrial functions under hypoxic conditions: The steady states of cytochrome c reduction and of energy metabolism. Biochem. Biophys. Acta, 347: 340–358.Google Scholar
- Warburg, O. and Kubowitz, F., 1929, Atmung bei sehr kleinen Sauerstoffdrucken, Biochem. Z., 214: 5–18.Google Scholar
- Wilson, D.F., Owen, C.S. and Erecidska, M., Drown, C., and Silver, I.A., 1979a, The oxygen dependence of cellular energy metabolism, Arch. Biochem. Biophys., 195: 485–493.Google Scholar
- Wilson, D.F., Erecinska, M., Drown, C. and Silver, I.A., 1977a, Effect of oxygen tension on cellular energetics, Amer. J. Physiol., 233 (5): C135 - C140.Google Scholar