Journal of Applied Physiology, Vol 81, Issue 2 810-815, Copyright © 1996 by American Physiological Society
Bronchial vascular reabsorption of low-protein interstitial edema liquid in perfused sheep lungs
M. Fukue, V. B. Serikov and E. H. Jerome
Cardiovascular Research Institute, University of California, San Francisco 94143, USA.
Previously, we quantified reabsorption of interstitial pulmonary edema
liquid into the pulmonary circulation during recovery from hydrostatic
edema. To determine whether the bronchial circulation also reabsorbs edema
liquid, we induced very-low-protein interstitial edema in seven sheep lungs
by perfusion of the pulmonary circulation with diluted blood and 1% albumin
in Krebs-Henseleit buffer containing 125I-labeled albumin for 70 +/- 40
min. In eight control sheep we perfused the lungs with diluted blood and 5%
albumin in Krebs-Henseleit buffer containing 125I-albumin without causing
significant edema formation. Subsequently, we washed the intravascular
tracer from the pulmonary circulation with buffered saline and then
perfused the bronchial vessels via the bronchoesophageal artery with whole
or diluted blood (normal protein osmotic pressure). We measured flow,
hematocrit, and 125I-albumin concentration in the venous outflow into the
left atrium and into the azygos vein for 2 h. We calculated the volume of
liquid reabsorbed on the basis of the change in hematocrit and 12I-albumin
concentration in the outflow. On the basis of hematocrit dilution, the net
clearance of interstitial liquid (edema minus control) averaged 21 ml (15%
of the induced edema). One the basis of 125I-albumin reabsorption, the net
clearance of interstitial liquid was 12 ml. We conclude that the bronchial
circulation may be a clearance route for interstitial liquid and protein
during recovery from low-protein hydrostatic edema.
