Background:Overloads of reactive oxygen species in diabetes are associated with a number of pathological conditions, such as endothelial damage, which plays an important role in the initial stage of atherosclerosis. Plasma soluble thrombomodulin (sTM) and von Willebrand factor (vWF) have been found to be important markers of endothelial dysfunction.Material/Methods: 33 male Wistar rats were used for this experiment. All rats received standard rat chow and water. 25 rats were made diabetic by intra peritoneal injection of streptozotocin (STZ) (65 mg/kg) and divided into three groups. Group I was allowed free access to food and water, Group II received 30 mg vitamin C daily, and Group III received a-tocopherol in a dose of 600 mg/kg body weight.Results: At the end of the experimental period, there was significant elevation of sTM, vWF, fibrinogen, systolic blood pressure, and mean arterial blood pressure (MAP); however, there was a significant decrease in serum HDL cholesterol in the diabetic group in comparison to controls. Administration of antioxidants (vitamin C and a-tocopherol) caused attenuation of the endothelial damage, as vitamin C administration caused a significant decrease in sTM, vWF, fibrinogen and increased HDL-cholesterol, while a-tocopherol caused a significant decrease in vWF and sTM. Both vitamin C and a-tocopherol caused a significant decrease in systolic blood pressure and mean arterial pressure.Conclusions: Our results suggest that administration of antioxidants may ameliorate the risk of thrombo-embolism in diabetes associated with hypertension.

Keywords: Antioxidants - pharmacology, Arteries - drug effects, Arteries - physiology, Ascorbic Acid - pharmacology, Biological Markers - blood, Blood Pressure - drug effects, Blood Pressure - physiology, Body Weight, Cholesterol, HDL - blood, Diabetes Mellitus, Experimental - blood, Diabetes Mellitus, Experimental - drug therapy, Diabetes Mellitus, Experimental - metabolism, Endothelium, Vascular - drug effects, Endothelium, Vascular - metabolism, Fibrinogen - analysis, Rats, Wistar, Thrombomodulin - blood, alpha-Tocopherol - pharmacology, von Willebrand Factor - analysis, Antioxidants - pharmacology, Arteries - physiology, Ascorbic Acid - pharmacology, Biological Markers - blood, Blood Pressure - physiology, Body Weight, Cholesterol, HDL - blood, Diabetes Mellitus, Experimental - metabolism, Endothelium, Vascular - metabolism, Fibrinogen - analysis, Rats, Wistar, Thrombomodulin - blood, alpha-Tocopherol - pharmacology, von Willebrand Factor - analysis