Acetate and arachidonate incorporations into lipids of ovine chorioallantoic tissue at day 24 of pregnancy.
Incorporation of acetate and arachidonic acid into lipid classes was examined in chorioallantoic membranes obtained from sheep at Day 24 of pregnancy. Conceptus tissues were incubated in vitro with 5 mM acetate, 0.042 mM arachidonate, 0.45 muCi [1-14C]acetate, and 5.0 muCi [5,6,8,9,11,12,14,15-3H]arachidonate for 3 and 6 h. After incubation, tissue lipid fractions were extracted, isolated, and examined for radiolabel incorporations. Medium was extracted and analyzed for radiolabeled metabolites. Metabolic pathways commonly associated with fatty acid metabolism were confirmed to be present. Acetate was utilized for de novo synthesis of free cholesterol and free fatty acid. Fatty acids containing radiolabel from both acetate and arachidonate were mainly esterified in phospholipid and triglyceride, major lipid classes found in chorioallantoic tissue. Labeled metabolites of acetate were not sufficient for analytical measurement in medium. Metabolites of arachidonic acid from lipoxygenase and cyclooxygenase pathways were determined in medium after incubation. Results suggest that, within Day 24 ovine chorioallantoic tissue, utilization of exogenous arachidonate and de novo lipogenesis from acetate function in a parallel and anabolic mode appropriate for membrane expansion.
Waterman
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Beltsville Agricultural Research Center, Agricultural Research Service, Maryland 20705.
Lewis
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D000085:Acetates / Q000378:metabolism*; D019342:Acetic Acid; D000482:Allantois / Q000378:metabolism*; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D002788:Cholesterol Esters / Q000378:metabolism; D002823:Chorion / Q000378:metabolism*; D004951:Esterification; D005321:Extraembryonic Membranes / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D007700:Kinetics; D050356:Lipid Metabolism; D008084:Lipoxygenase / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D012756:Sheep; D014280:Triglycerides / Q000378:metabolism
D000085:Acetates; D001095:Arachidonic Acids; D002788:Cholesterol Esters; D005227:Fatty Acids; D010743:Phospholipids; D014280:Triglycerides; D016718:Arachidonic Acid; D008084:Lipoxygenase; D011451:Prostaglandin-Endoperoxide Synthases; D019342:Acetic Acid