CAT and myocardial infarction: It has also been suggested that oxidative stress produced by free radicals or reactive oxygen species (ROS), as evidenced by marked increase in production of lipid peroxidative products associated with decreased levels of antioxidants such as superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH), plays a major role in myocardial damage during MI [5].