Effect of pulmonary lavage on lung lecithin synthesis in the Syrian hamster

Abstract

Bronchopulmonary lavage with 0.15 m saline stimulated the uptake of [1,2- 14C]choline into both the surface-active dipalmitoyl lecithin (DPL) and the unsaturated lecithins (UPC) of Syrian hamster lung. Labeling occurred in the tissue lecithins prior to label appearance in the lecithins in the alveolar space. In control lung tissue the rise in specific activity of saturated lecithin lagged behind that of the unsaturated lecithin fraction. The data were consistent with the view that alveolar lecithins are secreted by the tissue into the alveoli and that unsaturated lecithins are the precursors of dipalmitoyl lecithin. Labeled DPL and UPC were transferred from the tissue to the alveoli at approximately the same rate. Bronchopulmonary lavage did not greatly affect the rate of loss of label from alveolar lecithins. Type II cell proliferation, as measured by [ 3H]thymidine uptake, did not occur during the 18-hr period in which stimulated lecithin synthesis was observed.