The distribution and metabolism of α-tocopherol in the rat

Abstract

1. A comparison of the distribution of radioactivity in rat tissue lipids after oral administra- tion of [5-Me-¹⁴C]-α-tocopherol showed that spleen and adrenal lipids have a relatively high uptake of radioactivity. 2. Absorbed α-tocopherol and its metabolites appeared not to re-enter the lumen of the gut in significant amount through the bile or by the secretion from the stomach mucosal cells within the 24 h experimental period. 3. After ingestion of [5-Me-¹⁴C]-α-tocopherol by rats, analyses of their liver and spleen lipids showed that most of the radioactivity in the lipids was due to the presence of unchanged α-tocopherol. Radioactive tocopherolquinone was found in both spleen and liver lipids; in the liver lipids there was some evidence that a second oxidation product of α-tocopherol, compound O, had been formed.