lymphatic Absorption of Docosahexaenoic Acid Given as Monoglyceride, Diglyceride, Triglyceride, and Ethyl Ester in Rats

Abstract

Lymphatic absorption of docosahexaenoic acids (DHA) given as monoglyceride (MG), consisting of 1 (or 3)-species (91.4%), 2-species (4.2%) and diglyceride (DG) con-sisting of 1, 3-species (70.8%), 1 (or 3), 2-species (28.6%), were investigated in comparison with that of triglyceride (TG) and ethyl ester (EE). Rats were infused with a lipid emulsion containing 200 mg of DHA-MG, DG, TG, or EE via a gastric cannula. Lymph was collected through the thoracic lymph duct at 2h intervals for 10h and at a single collection from 10 to 30h. Physiological saline containing glucose was infused (2mL/h) throughout the lymph collection. The overall recovery of DHA at 30h after its infusion was significantly higher in the rank order DHA-MG>DG>TG=EE. Moreover, time-dependent changes in re-covery rates from 2 to 10h of DHA given as MG were significantly higher than those of the corresponding DG, TG, and EE. These results indicate that DHA-MG and DG are absorbed and transported more effectively than TG and EE forms under restricted water supply, even if they mainly consist of 1 (or 3)-species. Lymph lipids were mainly transported as TG, and a large amount of DHA was incorporated into a TG fraction in all fat types examined. Furthermore, the intramolecular distribution of DHA in lvmnh TG was similar in all grouns.