Journal of Applied Physiology, Vol 50, Issue 5 1065-1070, Copyright © 1981 by American Physiological Society
Role of albumin in prevention of edema in perfused rabbit lungs
R. S. Chang, K. Wright and R. M. Effros
Edema formation was studied using in situ rabbit lungs perfused with normal
5.0 g/dl) and low (0.1 g/dl) albumin solutions. Measurements were made of
the ratio of wet weight to dry weight of the lungs corrected for the
residual vascular volume, [(W/D)ev] and the ratio of extravascular 22Na+ to
extravascular water volume. Edema formation in the 5 g/dl lungs was
insignificant during a 60-min perfusion interval. A moderate amount of
edema was found in 0.1 g/dl lungs: (W/D)ev = 5.30 +/- 0.12 (SE) compared
with 4.66 +/- 0.11 in the 5 g/dl lungs. Much greater rates of edema
formation were found in the 0.1 g/dl lungs when left atrial pressures were
increased from 0 to 10 Torr; (W/D)ev reached 7.89 +/- 0.50 in 60 min
compared with 5.66 +/- 0.23 in the 5 g/dl lungs. No additional edema
formation occurred when albumin concentrations were decreased from 0.1 g/dl
to below 0.01 g/dl. Albumin concentration gradients across the capillary
wall appear to increase with elevations in capillary pressure.
