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

Abstract

The effect of dietary vitamin E on the synthesis of platelet thromboxane A2 (TxA2) and vascular prostacyclin (PGI2) in streptozotocin-induced diabetic rats was investigated. Thrombin-induced platelet TxA2 synthesis in diabetic rats was significantly elevated, whereas no significant difference was found with collagen-induced synthesis. Arterial PGI2 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 TxA2, vascular PGI2, 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 TxA2 than platelets from nondietary vitamin E-supplemented diabetic rats or nondiabetic controls.