torsSeveral enzymes have been shown to be involved in generation of ROS. For example, copper amine oxidase, catalyzes the oxidative deamination of polyamines, especially putrescine, and releases the ROS mediators hydrogen peroxide and ammonia.[5] Other enzymes thought to play a role in ROS production include xanthine oxidase, NADPH oxidase, oxalate oxidase, peroxidases, and flavin containing amine oxidases.