Studies of vanadyl sulfate as a glucose-lowering agent in STZ-diabetic rats.

To study the effect of vanadium (V) intake on blood glucose lowering, tissue V concentrations, glutathione reductase (GR) activity, and plasma trace metal concentrations, streptozotocin(STZ)-diabetic rats were treated with vanadyl sulfate (VS) (0.5-1.2 g/l in the drinking water) for up to 12 weeks. Kidney and plasma V concentrations were positively correlated with V intake. Kidney GR activities were not affected by VS treatment nor were plasma cobalt, molybdenum, manganese or lithium concentrations. Individual V intakes were dependent upon severity of diabetes, with more hyperglycemic rats consuming greater quantities of VS solution. A diminished effect on glucose lowering of VS above 1 g/l was noted.