VITAMIN-E-DEFICIENCY INCREASES SERUM THROMBOXANE-A(2), PLATELET ARACHIDONATE AND LIPID-PEROXIDATION IN MALE SPRAGUE-DAWLEY RATS

This study was designed to determine whether dietary linoleate and all-rac-alpha-tocopheryl acetate (vitamin E) interact to affect serum thromboxane A(2) (TXA(2)) and prostacyclin (PGI(2)) status and therefore, thrombogenic potential. 6 groups of 12 weanling male Sprague-Dawley rats were fed semipurified diets containing 11 or 18% of energy from linoleate and 0, 100 or 5000 mg vitamin E/kg diet for 10 weeks. Platelet and serum a-tocopherol concentrations increased logarithmically with increasing dietary vitamin E. Serum TXA(2), measured as TXB(2), platelet arachidonate and thiobarbituric acid reactive substances were significantly greater in the vitamin E deficient groups than in groups receiving vitamin E (p < 0.05). Serum PGI(2) levels, determined as 6-keto-PGF(1 alpha), were not affected by diets. No interaction was found between dietary linoleate and vitamin E. However, vitamin E supplementation produced significantly less serum TXB(2) than did vitamin E deficient diets (p < 0.05). Vitamin E deficiency may be prothrombogenic by increasing platelet arachidonate, lipid peroxidation and serum TXA(2) levels while vitamin E supplementation at levels used in this study may decrease such effects.