Mesenteric lymph absorption of eicosapentaenoic acid in rats

Abstract

Mesenteric lymph recoveries and profiles of labeled eicosapentaenoic acid were explored in rats after intraduodenal infusions of 90 μmol of lipid mixtures composed either of 5 μmol of eicosapentaenoic acid, 25 μmol of arachidonic acid, 30 μmol of oleic acid, and 30 μmol of monopalmitin or equimolar in eicopentaenoic acid, linoleic acid, and monoolein. Biochemical and morphologic studies were simultaneously carried out on mesenteric lymph lipoproteins. When administered in free form in the presence of monoglycerides, eicosapentaenoic acid absorption modalities closely resembled those of arachidonic acid given in a similar design, with a mesenteric lymph recovery of 44% of the infused radioactivity for the 6-h time period following the onset of the lipid infusion. In spite of 61–71% of eicosapentaenoic acid incorporation into lymph triglycerides, a significant incorporation into lymph phospholipids occurred (13–21%). By increasing the degree of unsaturation of the lipid mixture infused, the lymph lipoprotein size increased.