title: Absorption and transport of base moieties of phosphatidylcholine and phosphatidylethanolamine in rats.
abstract: The absorption and transport of the base moieties of phosphatidylethanolamine (PE) and phosphatidylcholine (PC) which were fed to rats were compared. The major absorption site of ethanolamine-labeled PE was proximal jejunum while choline-labeled PC was absorbed almost equally throughout the jejunum. Lysophospholipids, glycerophosphoryl bases and constituent bases were the main digested products in intestinal content. This shows that base-labeled phospholipids were hydrolyzed to water-soluble products as well as lysophospholipids before absorption. The radioactivities from both phospholipids existed mainly in their parent phospholipids and water-soluble products in the intestinal mucosa. The amounts of lymphatic transport of the radioactivities from choline-labeled PC and ethanolamine-labeled PE were 17% and 8%, respectively, at 8 h after administration. The liver in lymph-cannulated rats contained 23% and 48% radioactivity from PC and PE, respectively, suggesting that base moieties of phospholipids, especially PE, were transported mainly via a non-lymphatic route, probably the portal vein, to the liver, as water-soluble products. The radioactivity from both base-labeled phospholipids in the liver was distributed in the parent phospholipids and water-soluble fractions. Ethanolamine-labeled PE was also incorporated into PC in the liver. These results indicate that intestinal absorption and transport of the base moiety of dietary PC and PE are similar; however, their intestinal absorption site and the extent of their separation during transport between the lymphatic and portal systems differ markedly.
mesh_terms: D000818:Animals; D001692:Biological Transport; D002794:Choline / Q000493:pharmacokinetics; D004041:Dietary Fats / Q000378:metabolism; D019856:Ethanolamine; D004983:Ethanolamines / Q000493:pharmacokinetics*; D007408:Intestinal Absorption; D007583:Jejunum / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008208:Lymphatic System / Q000378:metabolism; D010713:Phosphatidylcholines / Q000493:pharmacokinetics*; D010714:Phosphatidylethanolamines / Q000493:pharmacokinetics*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D004041:Dietary Fats; D004983:Ethanolamines; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D019856:Ethanolamine; D002794:Choline