Changes in the concentrations of vitamin E analogs and their metabolites in rat liver and kidney after oral administration

Abstract

Vitamin E analog, such as α- and γ-tocopherol, can undergo ω-oxidation without cleavage of the chroman ring, and this pathway is responsible for generation of the major urinary vitamin E metabolite, carboxyethyl hydroxychroman. However, it is still unclear how carboxyethyl hydroxychroman is changed in various tissues after vitamin E intake. We therefore investigated changes in the concentrations of α- and γ-tocopherol and their metabolites in rat liver and kidney. The concentration of α-tocopherol in rat liver increased until 6 h after oral administration, and then decreased. The change in the concentration of α-carboxyethyl hydroxychroman in rat liver in the α-Toc group slowly increased until 12 h after oral administration. Cytochrome P450 3A1 mRNA expression significantly increased from 12 h after the start of α-tocopherol administration. The change in the concentration of γ-carboxyethyl hydroxychroman in rat liver in the γ-Toc group markedly increased until 12 h after oral administration. On the other hand, γ-carboxyethyl hydroxychroman in rat kidney showed greater accumulation than α-carboxyethyl hydroxychroman from 3 h to 24 h after oral administration. From these results, we considered that γ-carboxyethyl hydroxychroman formed in the liver continues to be released into the bloodstream and is transported to the kidney rapidly.

A Genome-wide Association Study Discovers 46 Loci of the Human Metabolome in the Hispanic Community Health Study/Study of Latinos

“…We utilized three large GWAS summary statistics and identified two causal pathways for CHD and one causal pathway for T2D. Allele C of an intergenic variant, rs79400241, located downstream of CYP4F2 involved in catabolism of vitamin E, 69 is associated with increased levels of gamma-CEHC and gamma-CEHC glucuronide. Both metabolites are vitamin E derivatives, 70 and gamma-CEHC possesses antioxidant and natriuretic properties.…”