INHIBITION OF SELENITE-CATALYZED SUPEROXIDE GENERATION AND FORMATION OF ELEMENTAL SELENIUM (SE-DEGREES) BY COPPER, ZINC, AND AURINTRICARBOXYLIC ACID (ATA)

Selenite catalyzes the oxidation of glutathione (GSH) with the subsequ ent generation of superoxide (O-2 .(-)). Copper, zinc, and aurintricar boxylic acid (ATA) were tested for their ability to inhibit both the s elenite-catalyzed generation of superoxide and the conversion of selen ite to elemental selenium (Se degrees). As measured by lucigenin-depen dent chemiluminescence (CL), copper, zinc, and ATA were shown to inhib it significantly (P < 0.05) selenite-catalyzed CL in a concentration d ependent manner. The inhibition of the selenium-catalyzed generation o f superoxide by copper(II) was greater than by either zinc or ATA. In addition, Copper, zinc, and ATA all inhibited the conversion of seleni te to Se degrees. Inhibition of selenite-catalyzed CL by copper, zinc, and ATA is believed to occur as the result of inhibition of Se2- and/ or GSSe(-), the catalytic selenopersulfide anion of GSH.