A comparison of the intestinal absorption, lymph and plasma transport, and tissue uptake of α- and γ-tocopherols in the rat

Abstract

1. 1. The intestinal absorption into lymph of α- and γ-tocopherols was studied in rats with mesenteric lymph cannulae. γ-Tocopherol was consistently absorbed to an extent 15% lower than that of α-tocopherol. Both appeared in the lymph unchanged and were distributed similarly among the lymph lipoproteins. 2. 2. When a mixture of α- and γ-tocopherols bound to chylomicrons and very low density lipoproteins was injected intravenously into rats, the distribution of the two tocopherols in the plasma lipoproteins was similar. A detailed study of the lipo-protein distribution of α-tocopherol, cholesterol, triglyceride and phospholipid in rat plasma revealed that α-tocopherol was not specifically associated with any one lipo-protein group, but that its distribution most nearly resembled that of total lipid. 3. 3. α-Tocopherol and γ-tocopherol after intravenous injection were equally taken up from plasma by red cells and liver, but there was an initial preferential uptake of γ-tocopherol by the spleen. After 24 h, all tissues had lost γ-tocopherol more rapidly than γ-tocopherol.