In vitro effects of alloxan-vanadium combination on lipid peroxidation and on antioxidant enzyme activity.

1. The in vitro effects of alloxan, dialuric acid and vanadium ions, alone or in combination, on lipid peroxidation and on antioxidant enzyme activity in rat liver and kidney were studied. 2. Unlike alloxan, alloxan-glutathione (GSH) and dialuric acid increased lipid peroxidation, which could be explained by the decreased activity of catalase and GSH peroxidase during incubation. 3. Vanadium(IV) ions increased the amount of thiobarbituric acid-reacting substances, but neither vanadium(IV) nor vanadium(V) changed the enzyme activity. 4. The combination of vanadium ions and alloxan-GSH or dialuric acid had no additive effect on lipid peroxidation. Vanadium ions decreased the dialuric acid-induced inhibition of catalase activity. 5. The present results suggest the therapeutic value of vanadium as an antidiabetic agent.