Metabolic conversion of platelet-activating factor into ethanolamine plasmalogen in an amnion-derived cell line.
Platelet-activating factor (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine, PAF) labeled with 3H in the alkyl side chain was taken up rapidly by amnion-derived WISH cells in culture. The radioactivity was found in a number of cellular metabolites, principally 1-O-alkyl-2-acyl-sn-glycero-3-phosphocholine (alkyl-acyl-GPC) which was labeled at a rapid rate. No intracellular accumulation of lyso-PAF was detected. At longer time periods, a substantial proportion of the radioactivity was found in association with the phosphatidylethanolamine fraction extracted from the cells. This fraction contained a high proportion of the corresponding 1',2'-alkenyl derivative (plasmalogen), as judged by the formation of long-chain fatty aldehyde after exposure to acid. The magnitude of the conversion of PAF into ethanolamine plasmalogen is suggestive of a correlation between plasmalogen content and exposure to PAF in some tissues. The exact sequence of reactions leading from alkyl-acyl-GPC to the ethanolamine derivatives is yet to be established.
Frenkel
R A
RA
Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235.
Johnston
J M
JM
D000650:Amnion / Q000378:metabolism*; D001692:Biological Transport; D002478:Cells, Cultured; D006801:Humans; D066298:In Vitro Techniques; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D010955:Plasmalogens / Q000378:metabolism*; D010972:Platelet Activating Factor / Q000378:metabolism*
D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010955:Plasmalogens; D010972:Platelet Activating Factor; C020791:phosphatidal ethanolamines