A novel mechanism of diglyceride formation. 12-O-tetradecanoylphorbol-13-acetate stimulates the cyclic breakdown and resynthesis of phosphatidylcholine.
12-O-Tetradecanoylphorbol-13-acetate (TPA) treatment of Madin-Darby canine kidney cells resulted in an increased incorporation of 32Pi and [methyl-3H]choline into choline-containing phosphoglycerides (PC). In pulse-chase experiments, TPA treatment caused an increased release of [methyl-3H]choline from the PC fraction of prelabeled cells. When cells were prelabeled with [3H]arachidonic acid and [14C]palmitic acid, TPA treatment resulted in an increased synthesis of 14C, 3H-diglycerides. Further studies were done to determine the relationship between PC breakdown and diglyceride synthesis. Cells were preincubated with ether-linked 1-O-[3H]hexadecyl-2-lyso-sn-glycero-3-phosphocholine which was acylated to form 1-O-[3H]hexadecyl-2-acyl-sn-glycero-3-phosphocholine. Subsequent treatment of these cells with TPA resulted in an increased synthesis of 1-O-[3H]hexadecyl-2-acyl-sn-glycerol compared to cells not stimulated with TPA. These findings demonstrate that TPA stimulates PC turnover in Madin-Darby canine kidney cells and provide evidence for a novel mechanism of diglyceride formation.
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism; D002460:Cell Line; D002794:Choline / Q000378:metabolism; D004075:Diglycerides / Q000096:biosynthesis*; D004285:Dogs; D005989:Glycerides / Q000096:biosynthesis*; D007668:Kidney; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism; D010704:Phorbols / Q000494:pharmacology*; D010710:Phosphates / Q000378:metabolism; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D010714:Phosphatidylethanolamines / Q000096:biosynthesis; D010972:Platelet Activating Factor / Q000031:analogs & derivatives / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D001095:Arachidonic Acids; D004075:Diglycerides; D005989:Glycerides; D010169:Palmitic Acids; D010704:Phorbols; D010710:Phosphates; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010972:Platelet Activating Factor; D016718:Arachidonic Acid; D019308:Palmitic Acid; C037145:1-hexadecyl-2-acetyl-glycero-3-phosphocholine; D002794:Choline; D013755:Tetradecanoylphorbol Acetate