Influence of dietary vitamin E on prostaglandin biosynthesis in rat blood.

A vitamin E (alpha-tocopherol) deficient diet stimulated prostaglandin biosynthesis in coagulating rat blood. Prostaglandins were extracted from serum, purified and bioassayed. The identity of prostaglandin E2 was confirmed by gas chromatography-mass spectrometry. Withholding vitamin E from the diet caused a marked increase in PGE2 and a lesser increase in PGF2alpha production in serum. In rats maintained on diets containing different concentrations of vitamin E, serum concentrations of PGE2 and PGF2alpha were inversely related to serum concentrations of alpha-tocopherol. These data suggest that in vitro alpha-tocopherol inhibits the endogenous conversion of arachidonic acid into PGE2 and PGF2alpha. The possibility that alpha-tocopherol may inhibit the formation of endoperoxide intermediates of PGE2 and PGF2alpha biosynthesis and subsequent induction of platelet aggregation is discussed.