Effects of superoxide dismutase on the auto-oxidation of 7, 8-dihydroxychlorpromazine in the presence of rat brain mitochondria.

7,8-Dihydroxychlorpromazine 7,8-diOH-CPZ) is known to undergo auto-oxidation when exposed to air. Hydrogen peroxide is formed during this process, and the amount formed can be calculated from the amount of oxygen produced upon the addition of catalase. In the presence of superoxide dismutase the rate of oxidation of the CPZ metabolite is accelerated, accompanied by an increased production of hydrogen peroxide. When similar incubation are carried out with rat brain mitochondria present, hydrogen peroxide production is no longer detectable. The implications of this finding with regard to in vivo hydrogen peroxide production during the auto-oxidation of 7,8-diOH-CPZ are discussed. A preliminary report has been presented (1).