Journal of Applied Physiology, Vol 44, Issue 3 353-357, Copyright © 1978 by American Physiological Society
Solute permeability of the alveolar epithelium in alloxan edema in dogs
R. M. Nelson, B. R. McIntyre and E. A. Egan
The permeability of the alveolar epithelium following alloxan challenge was
studied in dogs by determining transfer of radiolabeled solutes between
alveolus and blood. Two days after injection of 131-Ialbumin into the
blood, anesthetized dogs had the air space of part of one lung isolated by
a balloon catheter lodged in a bronchus. We infused the
atelectatis-isolated area with normal saline containing trace amounts of
Blue Dextran, 125Ialbumin, and 57Co-cyanocobalamin; challenged six animals
with intravenous alloxan, and six animals with alloxan added to the
alveolar saline. During the pulmonary edema, 57Co-cyanocabalamin and
125I-albumin appeared in the blood and 131I-albumin entered the alveolar
saline. The animals challenged by alveolar instillation showed a greater
permeability change (P less than 0.05). The bidirectional transfer of
macromolecules indicates that alloxan produces a change in the permeability
of the alveolar epithelium, allowing diffusional exchange of
macromolecules. Since alveolar flooding in hemodynamic edema does not show
a similar change in the permeability of the epithelial lining, alveolar
flooding in alloxan edema is not due solely to an effect on the endothelial
membrane, but also to a direct effect on the epithelial membrane.
