THE EFFECT OF ALUMINUM ON THE VANADIUM-MEDIATED OXIDATION OF NADH

Aluminum catalyzes the oxidation of NADH by vanadate both in the prese nce and absence of a reducing sugar, The effect of aluminum is concent ration dependent and inhibitable with superoxide dismutase but not cat alase. The fructose-6-phosphate-free reaction is characterized by an i nitial lag phase which can be eliminated by preincubating aluminum wit h NADH, but is not altered by preincubating aluminum with vanadate, su ggesting that the effect. of aluminum is not directly on vanadate. Alu minum also catalyzes vanadyl-mediated oxidation of NADH, and this effe ct is similarly inhibitable by superoxide dismutase as well as catalas e. It is suggested that aluminum catalyzes the oxidation of NADH by va nadium though enhancing the production of superoxide radicals and that this effect may account in part of the biological toxicity associated with aluminum, particularly when associated with the accumulation of other trace elements such as vanadium..