Pulmonary lipid composition of species with and without surfactant

Abstract

Pulmonary lipids were analyzed in species with high surface activity (man and dogs), in species with deficient surface activity (frogs, turtles, and chickens), and after pulmonary artery occlusion, which is associated with loss of surface activity. The total phospholipid content of the lung was significantly higher in situations with high surface activity. The relative proportions of the identified phosphatides (sphingomyelin, lecithin, phosphatidyl inositol/ serine, phosphatidyl ethanolamine, and lysolecithin) were not different. The fatty acid esters of these phosphatide fractions were more characteristic of the phospholipid than of the specific source. Lecithin was the major phospholipid and palmitic acid the predeominant fatty acid ester of this phosphatide. There was no positional specificity for the fatty acid esters of lecithin. The proportion of saturated fatty acid esters in all phosphatide fractions was increased in atelectatic lung after pulmonary artery occlusion. Quantitative differences in pulmonary phospholipids are associated with differences in surfactant related to species and to pulmonary artery occlusion.