Restoration of Prostacyclin/Thromboxane A2 Balance in the Diabetic Rat: Influence of Dietary Vitamin E

The effect of dietary vitamin E on the synthesis of platelet thromboxane A 2 (TxA 2 ) and vascular prostacyclin (PGI 2 ) in streptozotocin-induced diabetic rats was investigated. Thrombin-induced platelet TxA 2 synthesis in diabetic rats was significantly elevated, whereas no significant difference was found with collagen-induced synthesis. Arterial PGI 2 production was significantly decreased in diabetic rats. Serum lipid peroxide levels were elevated, and platelet vitamin E levels decreased in diabetic rats. When the diabetic rats were maintained on a high vitamin E diet for 2-3 mo, thrombin-induced platelet TxA 2 , vascular PGI 2 , and lipid peroxides were restored to levels found in nondiabetic rats. Platelets from diabetic rats maintained on a high vitamin E diet synthesized significantly less collagen-induced TxA 2 than platelets from nondietary vitamin E-supplemented diabetic rats or nondiabetic controls.