Effects of vanadyl sulphate on glucose homeostasis in severe diabetes induced by streptozotocin in rats.

ABSTRACT

Rats made severely diabetic by an i.v. injection of 50-55 mg/kg streptozotocin (STZ), 15 days later showed blood glucose > 500 mg/dl, quadrupled daily water intake and plasma insulin of 14 +/- 3 microU/ml, about 25 per cent that of normal rats. Subsequently, these rats in two groups, received 0.5-1 mg/ml vanadyl sulphate in base solution (vanadyl) orally (Group I) and base solution containing 50 mEq/1 NaCl (Group II). Since 90 days of vanadyl therapy could not decrease blood glucose of group I (420 +/- 10 mg/dl) to normal levels, euglycaemia was achieved for a period of two months by intraperitoneal (i.p.) injection of NPH insulin. The required daily doses of insulin in vanadyl-treated rats of group I (8 +/- 1 U/kg/day) were only 8 per cent of those in group II animals (103 +/- 7 U/kg/day). In conclusion, it seems that vanadyl per se cannot induce normoglycaemia in diabetic rats with very low plasma insulin levels, but can augment the sensitivity of peripheral tissues to insulin.