Journal of Applied Physiology, Vol 47, Issue 4 692-700, Copyright © 1979 by American Physiological Society
Effect of lung surface tension on bronchial collapsibility in excised dog lungs
M. Nakamura, H. Sasaki and T. Takishima
Bronchial collapsibilities were studied in air- and saline-filled excised
dog lungs. The intrapulmonary bronchi were isolated from the rest of the
lung parenchyma with beads placed at their tributary bronchi as described
previously by Takishima et al. (J. Appl. Physiol. 38: 875-881, 1975).
Pressure-volume relations of the isolated bronchi were obtained while lung
volume (VL) was kept constant. When lung recoil pressure (PL) was reduced
by filling the lung with saline at a given VL, bronchial areas were smaller
and bronchial collapsibilities were larger than in the air-filled lung.
When bronchial areas and bronchial collapsibilities in air- and
saline-filled lungs were compared at a given PL, they were approximately
identical. We concluded that bronchial areas and collapsibilities were
primarily determined by PL rather than VL, and lung surface tension itself
made bronchial collapsibility equal to or even less than the degree of
collapsibility due to forces applied from surrounding lung tissues that
distended the bronchi.
