One-year treatment of streptozotocin-induced diabetic rats with vanadyl sulphate.

Streptozotocin-diabetic and non-diabetic rats were given various concentrations of vanadyl sulphate in drinking water for one year. It was found that vanadyl sulphate caused significant decreases in body weight gain and plasma insulin level in non-diabetic rats, but did not significantly alter fluid and food intakes or plasma levels of glucose, triglycerides, or cholesterol. In diabetic animals, vanadyl treatment significantly alleviated or prevented the occurrence of hyperglycaemia, hypoinsulinaemia, hyperphagia, polydipsia, hyperlipidaemia, or cataract formation, but the slower body weight gain was not improved. There were gradual decreases in the intake of the compound required to correct hyperglycaemia in the values of ED50 with age of the rats. The beneficial effects of vanadyl treatment persisted 16 weeks following the withdrawal of the compound. It is concluded that vanadyl sulphate is an effective agent for chronic therapy of streptozotocin-induced diabetes in rats, and its prolonged use does not lead to the development of tolerance.