Abstract
We have shown the decrease in surface activity in pathological change of the lung; chronic simple atelectasis, and pneumonia.
Recently it has shown that the production of surfactant in alveolar cells was dependent on the blood flow in the lungs whether it was pulmonary or bronchial circulation.
In the present studies the change in surface activity was investigated after pulmonary vein ligation in rabbits. The lungs showed liver-like appearance 48 hours after pulmonary vein ligation and the value of stability ratio (SR) decreased with the average of 0.36±0.21. The mean values of γmin and S measured with surface balance were 21.3±3.0dynes/cm and 0.77±0.17 respectively. Hystersis loop on surface tension-area diagram was very narrow. There was no significant change in SR of the lung after sham operation, and 48 hours after autogenous blood was injected into the normal lung through trachea, nor 1 hour after the injection of blood into the subpleural lung tissue.
The values of SR of the 5 rabbits sacrificed longer than 35 days following pulmonary vein ligation returned to the control and the lobe with ligated pulmonary vein was inflated and showed no atelectasis except pleural adhesion.
These results indicate that the circulatory disturbance induced by ligation of pulmonary vein produces the decrease in surface activity and this change returns to the normal following collateral circulation may develop.
