Transacylation of 1-O-alkyl-SN-glycero-3-phosphocholine (lyso platelet-activating factor) and 1-O-alkenyl-SN-glycero-3-phosphoethanolamine with docosahexaenoic acid (22:6 omega 3).
[14C]22:6 (docosahexaenoic acid) was rapidly incorporated into cellular lipids in rabbit alveolar macrophages. After removal of free [14C]22:6, the radioactivity in diacyl-glycerophosphocholine (GPC) gradually decreased with a concomitant increase in [14C]22:6 in alkylacyl-GPC and alkenylacyl-glycerophosphoethanolamine (GPE), indicating that [14C]22:6 was transferred from diacyl-GPC to these ether lipid fractions. In fact, macrophage microsomes were shown to catalyze the transfer of [14C]22:6 from exogenously added diacyl-GPC to 1-alkyl-GPC (lyso platelet-activating factor) and 1-alkenyl-GPE. These results are the first evidence for the involvement of the transacylation system in the metabolism of C22 polyunsaturated fatty acids and lyso platelet-activating factor.
D000215:Acylation; D000818:Animals; D003065:Coenzyme A / Q000502:physiology; D004281:Docosahexaenoic Acids; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D066298:In Vitro Techniques; D008264:Macrophages / Q000378:metabolism; D008861:Microsomes / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism*; D010972:Platelet Activating Factor / Q000031:analogs & derivatives* / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000378:metabolism; D011817:Rabbits
D005231:Fatty Acids, Unsaturated; C029271:O-deacetyl platelet activating factor; D010714:Phosphatidylethanolamines; D010972:Platelet Activating Factor; D004281:Docosahexaenoic Acids; D003065:Coenzyme A