AJP - Regulatory, Integrative and Comparative Physiology, Vol 252, Issue 2 341-R347, Copyright © 1987 by American Physiological Society
Does myoglobin contribute significantly to diffusion of oxygen in red skeletal muscle?
D. G. Covell and J. A. Jacquez
We have examined the role of myoglobin to facilitate O2 diffusion to active
mitochondria in skeletal muscle by constructing computer-simulation
experiments. Steady-state mitochondrial O2 consumption under different
conditions of supply partial pressure of O2 (PO2) in a system with and
without myoglobin were examined for a one-dimensional slab of tissue. O2
consumption by mitochondria was saturable with the mitochondria located in
bands at uniform intervals throughout the tissue. Under these conditions,
myoglobin provides a measurable increase in O2 transport for supply PO2
below 10 Torr and diffusion lengths expected for skeletal muscle fibers. We
conclude that under circumstances where hypoxia lowers PO2 below 10 Torr
that myoglobin begins to provide a measurable increase in O2 delivery to
mitochondria.
