Lipid peroxidation and antioxidants as biomarkers of tissue damage.

Disturbance of the balance between the production of reactive oxygen species such as superoxide; hydrogen peroxide; hypochlorous acid; hydroxyl, alkoxyl, and peroxyl radicals; and antioxidant defenses against them produces oxidative stress, which amplifies tissue damage by releasing prooxidative forms of reactive iron that are able to drive Fenton chemistry and lipid peroxidation and by eroding away protective sacrificial antioxidants. The body has a hierarchy of defense strategies to deal with oxidative stress within different cellular compartments, and superimposed on these are gene-regulated defenses involving the heat-shock and oxidant stress proteins.