Objective:

Use of the trace element vanadium in the treatment of diabetes mellitus is being investigated because of its association with the regulation of glucose metabolism. Because some aspects of vanadium metabolism appear to be related with iron, this study was designed to determine whether treatment with vanadium maltolate in a rat model of diabetes affected iron bioavailability in the liver.

Methods: 

Four groups of male Wistar rats were used: Control animals, rats treated with vanadium maltolate (7 mg V/kg body weight), untreated streptozotocin (STZ)-diabetic rats, and STZ-diabetic rats treated with vanadium maltolate (7 mg V/kg body weight). Aliquots of homogenized liver samples were acid-digested in a microwave digestion system. Total metal content was analyzed with inductively-coupled plasma mass spectrometry, evaluating the accuracy of the method by the analysis of a bovine muscle certified reference material, and studies of recovery in samples of liver enriched with multielementary standards.

Results: 

Treatment with vanadium maltolate significantly increased vanadium and iron stores in the liver in control rats (P<0.001 and P<0.01, respectively) and STZ-diabetic rats (P<0.001 and P<0.05 respectively). Concentrations of vanadium and iron in the liver showed a linear correlation (r =0.60, P< 0.001).

Conclusion: 

Treatment with vanadium maltolate increased iron deposits in control rats and rats made diabetic with STZ. The increase appeared to be related to the ability of vanadium to enhance iron uptake by storage proteins (unpublished results) in hepatocytes.