Synthesis of Dipalmitoyl Lecithin by Lung and Alveolar Macrophages

Abstract

Dipalmitoyl lecithin (DPL) is the primary physiologic constituent of pulmonary surfactant. However, there is little direct information about its site of synthesis or pathway of synthesis. Alveolar macrophages (>90 percent pure by light microscopy and < 0.5 percent with lamellar bodies by electron microscopy), peritoneal exudates (> 90 percent heterophils), and slices of the lung and liver from rabbits were studied. Pure saturated lecithins were separated from other lecithins after formation of mercuric acid adducts. Saturated lecithin (> 96 percent palmitate) accounted for ca 20 percent of the total lecithin from saline washed alveolar macrophages and 30 percent of that from lung slices.