Functions of vitamin E in reproduction and in prostacyclin and immunoglobulin synthesis in rats.

The bioactivities of RRR-alpha-, beta-, gamma-, and delta-tocopherol (T) and R-alpha-tocotrienol (R-alpha-TT) were determined in rat resorption-gestation tests. The ranking order was RRR-alpha-T greater than RRR-beta-T greater than RRR-gamma-T greater than or equal to R-alpha-TT greater than RRE-delta-T. Accordingly, the biopotency of a palm-oil residue was assessed and expressed as alpha-tocopherol equivalents (alpha-TEs). The release of pyruvate kinase, a variable in the nutrition-linked necrotizing myopathy, into the plasma was dose-dependently inhibited by the RRR-alpha-T standard and the corresponding alpha-TE from this residue. Prostacyclin synthesis from aorta segments induced by thrombin or ionomycin was higher than the spontaneous release. However, there was no difference between the depleted group and groups treated with RRR-alpha-T or alpha-TEs from the palm-oil residue. Quantities of IgG in plasma of vitamin E-depleted rats were the highest. Upon supplementation with RRR-alpha-T or alpha-TEs from the palm-oil residue, reduced IgG concentrations were observed, similar to those of animals on a commercial diet containing adequate amounts of vitamin E.