Effect of vanadium compounds on calmodulin activity in experimental diabetes in rats

Vanadate and vanadyl have been reported to have insulin-like properties and have recently been demonstrated to be beneficial in the treatment of diabetic animals. In this study, we determined whether vanadium ions mimic the effect of insulin on calmodulin activity of liver and adipose tissues in streptozotocin-induced diabetic rats and examined their effect with respect to concentration and time. Calmodulin activities in the hormone-sensitive tissues decreased in diabetes and returned to normal after sodium metavanadate or vanadyl sulfate treatment for 3 weeks (0.2, 0.4, and 0.8 mg/mL in drinking water). These results demonstrate that V5+ and V4+ forms of vanadium can restore the activity of calmodulin in experimental diabetes induced by streptozotocin.