Absorption and transport of base moieties of phosphatidylcholine and phosphatidylethanolamine in rats

Biochim Biophys Acta. 1987 Sep 25;921(2):245-53.

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.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Biological Transport
  • Choline / pharmacokinetics
  • Dietary Fats / metabolism
  • Ethanolamine
  • Ethanolamines / pharmacokinetics*
  • Intestinal Absorption*
  • Jejunum / metabolism
  • Liver / metabolism
  • Lymphatic System / metabolism
  • Phosphatidylcholines / pharmacokinetics*
  • Phosphatidylethanolamines / pharmacokinetics*
  • Rats
  • Rats, Inbred Strains

Substances

  • Dietary Fats
  • Ethanolamines
  • Phosphatidylcholines
  • Phosphatidylethanolamines
  • Ethanolamine
  • Choline