title: Synthesis of the dipalmitoyl species of diacyl glycerophosphocholine by rabbit alveolar macrophages.
abstract: The distribution of radioactivity among the molecular species of diacyl glycerophosphocholine of rabbit alveolar macrophages was determined after incubation with [3H]glycerol and 1-[14C]palmitoyl-sn-glycero-3-phosphocholine. The highest percentage of radioactivity of [3H]glycerol was found in the dipalmitoyl species (35% of the total) followed by the 1-palmitoyl-2-linoleoyl (23.6%) and 1-stearoyl-2-linoleoyl plus 1-palmitoyl-2-oleoyl species (19.7%) during the first 30 min incubation. The radioactivity of the dipalmitoyl species reached a maximum at 120 min incubation and decreased thereafter, although the radioactivities of other molecular species still increased. In contrast to the [3H]glycerol labeling, only 4% of the total radioactivity in diacyl glycerophosphocholine derived from 1-[14C]palmitoyl glycerophosphocholine was found in the dipalmitoyl species; 80% of the radioactivity was located in the 1-palmitoyl-2-arachidonoyl species at 10 min incubation. The present results indicate that the dipalmitoyl species of diacyl glycerophosphocholine are synthesized predominantly via a de novo pathway and not the deacylation-reacylation pathway in rabbit alveolar macrophages.
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000031:analogs & derivatives*; D000818:Animals; D002250:Carbon Radioisotopes; D005227:Fatty Acids / Q000032:analysis; D005990:Glycerol / Q000378:metabolism; D008244:Lysophosphatidylcholines / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D011817:Rabbits; D011865:Radioisotope Dilution Technique; D014316:Tritium
chemical_list: D002250:Carbon Radioisotopes; D005227:Fatty Acids; D008244:Lysophosphatidylcholines; D010713:Phosphatidylcholines; D014316:Tritium; C006065:We 201; D015060:1,2-Dipalmitoylphosphatidylcholine; C039559:1,3-dipalmitoyl-2-phosphatidylcholine; D005990:Glycerol