Antioxidant enzymes 3.1. Superoxide dismutase 3.1.1. Glutathione peroxidase 4. Reactive oxygen species in pathophysiologic processes 5.
Reactive oxygen is related to both, the arrest of growth and the start of cell differentiation.
Low concentrations of reactive oxygen intermediates may be beneficial or even indispensable in processes such as intracellular messaging and defense against micro-organisms, but higher amounts of active oxygen may be harmful to cells and organisms. We describe their main characteristics and how these antioxidant enzymes work together against active oxygen. Consequently, toxic oxygen play a role in aging process as well as in a number of human diseases that we list in this review.