Journal of Applied Physiology, Vol 50, Issue 6 1115-1120, Copyright © 1981 by American Physiological Society
Oleic acid dose-related edema in isolated canine lung perfused at constant pressure
I. C. Ehrhart and W. F. Hofman
Fatty acid embolism of the lung results in pulmonary edema. Isolated lung
lobes ventilated and blood perfused at constant pressure were treated with
1 (n = 6) or 45 microliter/kg body wt (n = 6 oleic acid or saline (n = 7).
Lobe weight increase linearly over 1-3 h following oleic with regression
slopes indicating a more rapid rate of weight gain at the higher oleic acid
dosage. Total lobe weight gain was greater in the 45 than in the 1
microliter/kg group (0.60 +/- 0.10 vs. 0.31 +/- 0.07 g/g initial lobe wt)
and greater in the acid-treated lobes than in the controls (0.13 +/- 0.05
g/g initial lobe wt). Pulmonary vascular resistance increased 79% after 45
microliter/kg oleic acid but appeared unchanged following 1 microliter/kg
oleic acid or saline. The decrease in arterial O2 partial pressure was
greater in the 45 microliter/kg group than in the controls, 47 vs 22 Torr.
High vascular pressures and increased flow velocities in patent vessels are
not essential for oleic acid-associated edema, since weight increased at
constant pressure perfusion. Weight gain related to oleic acid dosage
suggests that oleic acid increases permeability by affecting the vascular
endothelium either directly or through biochemical intermediates endogenous
to the lung or blood.
