ABSTRACT
Diabetes mellitus is a very common health problem with a great impact in the individual health. Insulin dependent diabetes mellitus [IDDM] is believed to result from destruction of pancreatic beta cells secondary to toxic effects of free oxygen radicals, The diabetic patients are at a significant increase risk of developing cardiovascular diseases in general and coronary diseases in particular. The oxidative stress may play an important role in the etiology of diabetic complications. This oxidative stress is opposed by abundant supply of antioxidants. The antioxidants may play an important role in regulation of the level of plasminogen activator inhibitor 1 [PAI-1] which plays an important role in regulation of fibrinolysis. Also the fibrinolytic capacity of human blood is the result of a balance between plasminogen activators and inhibitors. The reent work was designed to study the effect of melatonin [antioxidant] treatment for eight weeks on serum levels of plasminogen activator inhibitor01 [PAI-I], Von willebrand factor [vwf], factor VII and triacylglycerol in streptozobtocin diabetic rats. Forty five adult male rats were divided into thee equal groups one served as a control, the other two groups were rendered diabetic by a single intraperitoneal injection of 50 mg/kg body weight streptozotocin [STZ]. One remained diabetic without melatonin treatment while the other group was given daily dose of 0.27 mg/kg. B.W. melaonin for eight weeks. Diabetic rats showed a significant increase in serum level of triacylglycerol, PAI-I, [vwf] and factor VII showed slight increase compared to non diabetic group. Treatment of diabetic rats with melatonin induced a significant decrease in serum levels of triacyglycerol, PAI-1, [vwf] and factor VII showed non significant decrease compared with diabetic group. We concluded that melatonin therapy induced a beneficial effect in STZ diabetic rats especially in a pattern of changes in serum levels of triacylglycerol, and the markers of endothelial dysfunction [PAI-I and vwf] that are related to induced risk of atherosclerosis