Arachidonic acid mobilization among phospholipids in murine mastocytoma P-815 cells: role of ether-linked phospholipids.
The ethanolamine-containing glycerophospholipids, choline-containing glycerophospholipids, and phosphatidylinositol fractions are major sources of arachidonic acid in murine mastocytoma P-815 cloned cells. The choline-linked fraction contained high arachidonic acid contents in 1-O-alkyl-2-acyl- (18%) and 1,2-diacyl-sn-glycero-3-phosphocholine (11%), with smaller amounts in 1-O-alk-1'-enyl-2-acyl species, whereas the arachidonic acid content of the ethanolamine-linked fraction was high in 1-O-alk-1'-enyl-2-acyl (26%) and 1,2-diacyl species (15%) and low in 1-O-alkyl-2-acyl species. The uptake and transfer of [3H]arachidonic acid into the 1,2-diacyl and ether classes of choline-containing glycerophospholipids and ethanolamine-containing glycerophospholipids in mastocytoma cells were examined. There was very rapid incorporation of radioactive arachidonic acid into mastocytoma cells that leveled off after 30 min. By labeling cells with [3H]arachidonic acid for 7.5 min, the radioactivity was recovered in the choline-containing glycerophospholipids (43%), phosphatidylinositol (32%), and ethanolamine-containing glycerophospholipids (20%) with little in other phospholipids, neutral lipid, or free fatty acid fractions. Upon reincubation of the mastocytoma cells in the radiolabel-free medium, the [3H]arachidonate radioactivity was gradually lost from the choline-containing glycerophospholipids fraction and, concomitantly, increased in ethanolamine-containing glycerophospholipids. At the zero time of reincubation, most of the radioactivity was recovered in the 1,2-diacyl species of both choline-containing glycerophospholipids and ethanolamine-containing glycerophospholipids.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D002460:Cell Line; D012515:Mast-Cell Sarcoma / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D010743:Phospholipids / Q000145:classification / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014316:Tritium
D001095:Arachidonic Acids; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D014316:Tritium; D016718:Arachidonic Acid