Journal of Applied Physiology, Vol 44, Issue 4 576-580, Copyright © 1978 by American Physiological Society
Quantitative changes in permeability of rat lung epithelium in lung edema
T. H. Gardiner
The pulmonary absorption of 14C-labeled urea, mannitol, inulin, and dextran
was measured in vivo in anesthetized rats with alpha-naphthylthiourea
(ANTU)-induced (5 mg/kg, ip) lung edema. At 1 h after ANTU treatment, the
absorption of mannitol was significantly increased; in 4-h ANTU-treated
animals, the absorption of urea was unchanged, whereas the absorption of
mannitol, inulin and dextran was increased markedly compared to controls.
Although disappearance of each solute from control lungs could be described
by a single, first-order rate, absorption time curves for mannitol and
inulin showed at least two components in edematous lungs: a fast
component(s) and a slower, first-order component; fast-component rates for
the two saccharides appeared to be similar; the slow-component rate for
each compound was not significantly different from its control rate. The
results suggest that fast-component absorption in ANTU-treated rats
represents a fraction of instilled solute which entered damaged areas of
lung where the porosity of the absorbing membranes was markedly increased,
whereas slow-component absorption occurred from normal areas of lung.
