Background and Aim: Perturbations in copper (Cu) metabolism are characteristic of diabetes type I. Hyperglycemia and increased free radicals generation result in increased Cu plasma levels and leads to oxidative stress. The aim of this study was to determine the antioxidant effects of ascorbic acid on Cu plasma levels in streptozotocin (STZ) induced diabetic rats.

  Materials and Methods: This study was done on 30 male wistar rats. Diabetes type I was induced in the rats by single intraperitoneal injection of streptozotocin (60 mg/kg). Four days after diabetes induction the animals showed hyperglycemia (>350mg/dL). After six weeks, the animals were divided into five groups as follows: controls, diabetics, diabetics treated with ascorbic acid, diabetics treated with insulin, and diabetics treated with insulin + ascorbic acid. Treatment was administered for two weeks and then plasma cu level was determined by atomic absorption method.

  Results: The results showed that in uncontrolled diabetes Cu plasma level increased significantly compared to of its level in the control group (P<0.05) whereas diabetic rats treated with insulin, insulin+ ascorbic acid or ascorbic acid showed no significant difference in Cu plasma level compared to those of control group (P>0.05).

  Conclusion: The results of this study indicate that treatment with insulin or ascorbic acid alone or in combination can preserve Cu plasma at normal level in diabetic rats.