Effects of vanadium compounds on diabetes induced changes in STZ-diabetic rats

Controversial reports on the efficacy and possible toxicity of vanadium obtained from various studies may be attributed to differences in the method of diabetes induction and/or to differences in animal strains. The objective of this study was to evaluate the contribution of these two factors to the effects of vanadium in the treatment of diabetes. Two methods of streptozotocin (STZ) induced diabetes in rats have been used for studying the antidiabetic effects of vanadium. One involves a single intravenous (i.v.) injection of 60 mg/kg STZ, and the other uses two subcutaneous (s.c.) injections of 40 mg/kg STZ, to either Wistar or Sprague Dawley (SD) rats. In a 7-week chronic study, SD rats appeared to develop a more severe diabetes (indicated by higher plasma cholesterol and higher fasting plasma glucose levels) following the single i.v. injection of STZ than rats made diabetic by two s.c. injections of STZ. Irrespective of the method of diabetes induction or the strain of rat, the responses of all the diabetic animals to vanadyl sulphate treatment were similar. In a 1-week acute study, Wistar diabetic rats were more responsive than SD diabetic rats to vanadyl sulphate and to lower doses (0.6 and 0.8 mmol/kg) of a new organic compound, bis(maltolato)oxovanadium(IV).Pharmaceutical Sciences, Faculty ofGraduat