Journal of Applied Physiology, Vol 53, Issue 5 1116-1124, Copyright © 1982 by American Physiological Society

ARTICLES

Mitochondrial function in the presence of myoglobin

R. P. Cole, P. C. Sukanek, J. B. Wittenberg and B. A. Wittenberg

The effect of myoglobin on oxygen consumption and ATP production by isolated rat skeletal muscle mitochondria was studied under steady-state conditions of oxygen supply. A method is presented for the determination of steady-state oxygen consumption in the presence of oxygen-binding proteins. Oxygen consumed in suspensions of mitochondria was replenished continuously by transfer from a flowing gas phase. Liquid-phase oxygen pressure was measured with an oxygen electrode; the gas-phase oxygen concentration was held constant at a series of fixed values. Oxygen consumption was determined from the characteristic response time of the system and the difference in the steady-state gas- and liquid-phase oxygen concentrations. ATP production was determined from the generation of glucose 6-phosphate in the presence of hexokinase. During steady-state mitochondrial oxygen consumption, the oxygen pressure in the liquid phase is enhanced when myoglobin is present. Functional myoglobin present in the solution had no effect on the relation of mitochondrial respiration and ATP production to liquid-phase oxygen pressure. Myoglobin functions in this system to enhance the flux of oxygen into the myoglobin-containing phase. Myoglobin may function in a similar fashion in muscle by increasing oxygen flux into myocytes.

This article has been cited by other articles:

				J. B. Wittenberg and B. A. Wittenberg Myoglobin-enhanced oxygen delivery to isolated cardiac mitochondria J. Exp. Biol., June 15, 2007; 210(12): 2082 - 2090. [Abstract] [Full Text] [PDF]

				D. L. Hoffman, J. D. Salter, and P. S. Brookes Response of mitochondrial reactive oxygen species generation to steady-state oxygen tension: implications for hypoxic cell signaling Am J Physiol Heart Circ Physiol, January 1, 2007; 292(1): H101 - H108. [Abstract] [Full Text] [PDF]

				P. S. Brookes, D. W. Kraus, S. Shiva, J. E. Doeller, M.-C. Barone, R. P. Patel, J. R. Lancaster Jr., and V. Darley-Usmar Control of Mitochondrial Respiration by NO., Effects of Low Oxygen and Respiratory State J. Biol. Chem., August 22, 2003; 278(34): 31603 - 31609. [Abstract] [Full Text] [PDF]

				J. B. Wittenberg and B. A. Wittenberg Myoglobin function reassessed J. Exp. Biol., June 15, 2003; 206(12): 2011 - 2020. [Abstract] [Full Text] [PDF]

				R. L. White and B. A. Wittenberg Mitochondrial NAD(P)H, ADP, oxidative phosphorylation, and contraction in isolated heart cells Am J Physiol Heart Circ Physiol, October 1, 2000; 279(4): H1849 - H1857. [Abstract] [Full Text] [PDF]

				E. Gnaiger, G. Mendez, and S. C. Hand High phosphorylation efficiency and depression of uncoupled respiration in mitochondria under hypoxia PNAS, September 26, 2000; 97(20): 11080 - 11085. [Abstract] [Full Text] [PDF]

				K. N. Richmond, R. D. Shonat, R. M. Lynch, and P. C. Johnson Critical PO2 of skeletal muscle in vivo Am J Physiol Heart Circ Physiol, November 1, 1999; 277(5): H1831 - H1840. [Abstract] [Full Text] [PDF]

				K. N. Richmond, S. Burnite, and R. M. Lynch Oxygen sensitivity of mitochondrial metabolic state in isolated skeletal and cardiac myocytes Am J Physiol Cell Physiol, November 1, 1997; 273(5): C1613 - C1622. [Abstract] [Full Text] [PDF]