Journal of Applied Physiology, Vol 38, Issue 4 588-592, Copyright © 1975 by American Physiological Society
Lung oxygen consumption and mitochondria of alveolar epithelial and endothelial cells
G. D. Massaro, D. B. Gail and D. Massaro
We examined oxygen consumption by lung slices and measured the volume
density of mitochondria of granular pneumocytes, alveolar type I cells, and
alveolar capillary endothelial cells in several species. We found that lung
oxygen consumption (mu-1 02 times h-1 times mg DNA-1) varies inversely with
the log of animal body weight and with the species alveolar diameter and
directly with the species respiratory rate. The volume density of granular
pneumocyte mitochondria show a direct linear correlation with the lung's
oxygen consumption and the species respiratory rate, and an inverse linear
correlation with the species alveolar diameter. The volume density of
mitochondria in type I alveolar epithelial cells and capillary endothelial
cells, considered together, did not differ in the two species studied
(mouse and rat). We conclude that there are interspecies differences in
oxygen consumption by lung cells and that granular pneumocytes contribute
to these differences. We suggest that, at least part of these differences,
are related to interspecies differences in surfactant secretory activity.
