ACUTE AND CHRONIC RESPONSE TO VANADIUM FOLLOWING 2 METHODS OF STREPTOZOTOCIN-DIABETES INDUCTION

Controversial reports on the efficacy and possible toxicity of vanadiu m obtained from various studies may be attributed to differences in th e method of diabetes induction and (or) to differences in animal strai ns. The objective of this study was to evaluate the contribution of th ese two factors to the effects of vanadium in the treatment of experim ental diabetes. Two methods of streptozotocin induction of diabetes in rats have been used for studying the antidiabetic effects of vanadium . One involves a single intravenous injection of 60 mg/kg streptozotoc in, and the other uses two subcutaneous injections of 40 mg/kg strepto zotocin, to either Wistar or Sprague-Dawley rats. In a 7-week chronic study, Sprague-Dawley rats appeared to develop a more severe diabetes (indicated by higher plasma cholesterol and higher fasting plasma gluc ose levels) following the single intravenous injection of streptozotoc in than rats made diabetic by two subcutaneous injections of streptozo tocin, Irrespective of the method of diabetes induction, the responses of all the diabetic animals to chronic vanadyl sulphate treatment wer e similar. In an acute study, Wistar diabetic rats were more responsiv e than Sprague-Dawley diabetic rats to vanadyl sulphate and to lower d oses (0.6 and 0.8 mmol/kg) of a new organic vanadium compound, bis(mal tolato)oxovanadium(IV).