A Du Nuoy tensiometer was used to study lung surfactant changes following heart-lung transplantation, pulmonary artery ligation, pulmonary hilar denervation, unilateral and bilateral vagotomy, and total cardiopulmonary denervation. There was a significant reduction in surfactant activity following pulmonary artery ligation, but no significant changes were found following any of the pulmonary denervation experiments. © 1969.
