Journal of Applied Physiology, Vol 39, Issue 2 235-241, Copyright © 1975 by American Physiological Society
"Closing volume" changes in alloxan-induced pulmonary edema in anesthetized dogs
R. Lemen, J. G. Jones, P. D. Graf and G. Cowan
"Closing volume" (CV) was measured by the single-breath oxygen (SBO2) test
in six dogs (alloxan group) before and after alloxan 100-200 mg/kg iv) was
injected. CV increased significantly (P less than 0.05) from 32 +/- 3.2%
(base line) to 45 +/- 3.5 % in period 1 (0-30 min after alloxan), but vital
capacity (VC), respiratory system pressure volume (PV) curves, and alveolar
plateau slopes did not change. No radiologic evidence of pulmonary edema
was demonstrated in two dogs studied in period 1. CV decreased to 20 +/-
3.9% during period 2 (30-80 min after alloxan) and was associated with
tracheal frothing, decreased VC, changes in the PV curve, and alveolar
plateau slope, as well as histologic evidence of severe pulmonary edema. CV
was 29 +/- 3.0%, and there were no changes in VC, PV curves, or alveolar
plateau slopes in 6 other dogs studied for 2 h (control group). CV
increased during period 1 before pulmonary edema could be demonstrated by
changes in VC, PV curves, or radiography, but in period 2 lung function was
so altered that CV by the SBO2 technique gave no useful information.
