DISTRIBUTION OF ALPHA-TOC STEREOISOMERS IN RATS

The distribution of alpha-tocopherol (alpha-Toc) stereoisomers in the tissues of rats fed on diets containing different levels of all-rac-al pha-tocopheryl acetate was determined by a newly revised HPLC method a nd compared with that of RRR-alpha-Toc fed rats. By this method, all-r ac-alpha-Toc in the blood and tissues was completely separated into 2R -isomers (one peak) and 2S-isomers (three peaks). The concentrations o f the 2R-isomers of alpha-Toc in the blood and tissues of the rats in the all-rac-alpha-tocopheryl acetate group were significantly higher t han those of the 2S-isomers. In most tissues, the level of 2S-isomers was in order of SRS > (SSS + SSR)/2 > SRR. In the RRR-alpha-Toc-fed gr oups, the concentration of RRR-alpha-Toc in every tissue depended on t he dose of alpha-Toc. When the concentration of 2R-isomers in the tiss ues of rats fed on all-rac-alpha-Toc (100 mg/kg diet) is compared with the concentration of RRR-alpha-Toc in the tissues of rats fed on RRR- alpha-Toc (50 mg/kg diet) the concentration of 2R-isomers in every tis sue of the former is the same as the RRR-alpha-Toc concentration of th e latter.