The Effect of Myoglobin Concentration on on Muscle Cell PO₂ Gradients

Abstract

The role of myoglobin in facilitating oxygen transport in red muscle cells has been well studied. Experimental findings by Wittenberg et al. (1975) in pigeon breast muscle, de Koning et al. (1981) in chicken gizzard smooth muscle, Stevens and Carey (1981) in muscles of tuna and other warm-bodied fish, and Cole (1982) in isolated dog gastrocnemius-plantaris muscle indicate the physiological importance of myoblobin for oxygen delivery to muscle mitochondria. Theoretical models have been developed (c.f. Wyman, 1966; Murray, 1974; and Taylor and Murray, 1977) to describe the myoglobin-facilitation of oxygen transport in muscle tissue. The question still remains, however, concerning the magnitude of intra-muscle cell oxygen gradients and the quantitative effect of the muscle myoglobin concentration on the intracellular oxygen gradients. The purpose of this paper is to extend the model of Murray (1974), describing the steady-state oxygen uptake of a muscle fiber, to explore the specific effect of myoglobin concentration on intra-muscle cell gradients of oxygen tension.