Abstract
Lung and liver slices were incubated with 2-3H-glycerol and U-14C-palmitate and the incorporation of radioactivities into various lipid classes and their subfractions with both precursors were examined. (1) The incorporation of both precursors into phosphatidic acid and diglyceride was much smaller in lung than in liver, but the incorporation into phosphatidylcholine and triglyceride was exactly the opposite. (2) The incorporation of 3H-glycerol into various subfractions was highest in the oligoenoic fraction both in phosphatidic acid and diglyceride, in dienoic subfraction in phosphatidylcholine, and in the polyenoic subfraction in phosphatidylethanolamine and phosphatidylinositol in both liver and lung. (3) The ratios of 14C/3H were higher in phosphatidylcholine than in phosphatidic acid and diglyceride, both in lung and liver. The highest ratio was found in the saturated species of phosphatidylcholine among these lipids in lung. (4) Some discussions were made concerning the formation pathways of dipalmitoyl species in lung.
