Am. J. Respir. Crit. Care Med., Vol 150, No. 3, Sep 1994, 784-789.
Lung capillary albumin leak in oxygen toxicity. A quantitative immunocytochemical study
KL Weir, EN O'Gorman, JA Ross, DJ Godden, AD McKinnon and PW Johnston
Department of Pathology, University of Aberdeen, Scotland.
The study is based on the hypothesis that lung endothelial cell
permeability increases in 100% oxygen and predates the appearance of
microscopically visible interstitial edema. Rats were exposed to either
100% oxygen or air in a chamber. Endogenous albumin was used as an index of
permeability and measured by electron microscopic colloidal gold linked
immunocytochemistry, quantified by systematic random methods. Albumin
staining was expressed as relative albumin concentration (RAC), the ratio
of gold particles (x 100) per point counted (gp.10(2)/pt) relating to each
component. The RAC in lung perivascular/peribronchial interstitial ground
substance after 24 h of hyperoxia was five times more than that of rats
exposed to air for the same interval. The median value (interquartile
ranges) for the oxygen- exposed group was 92.4 (39.5, 149.6) gp. 10(2)/pt
compared with 14.7 (6.6, 25.9) gp. 10(2)/pt for the air-exposed group.
After 60 h of 100% oxygen, the RAC was 103.4 (65.5, 148.9) gp. 10(2)/pt
(60-h air exposed RAC was 11.6 (8.7, 60.4) gp. 10(2)/pt), no different from
24-h exposures. These results suggest that there was a significant leak of
albumin to the perivascular/peribronchial interstitium by 24 h of exposure
to 100% oxygen, which would indicate endothelial cell permeability to
albumin increases earlier than has previously been reported.
