ABSTRACT
The first step in addressing the role of oxidative stress (OxS) in diabetic com plications is to define OxS. It is often defined as a shift in the pro-oxidantantioxidant balance in the pro-oxidant direction. This definition of OxS is more descriptive than quantitative and chemical in nature. Philosophically, it implies a null point, a balance point at which there is no OxS-OxS occurs only when the balance is shifted toward the pro-oxidant direction. There is a conceptual flaw in this definition because it fails to recognize that OxS is a constant feature of biological systems. Peroxides, superoxide, hydroxyl radicals, and other re active oxygen species (ROS), the mediators of OxS, are being formed continu ously in the body and always exist at some steady-state concentration. The resulting oxidative damage to protein, DNA, and other biomolecules is a ubiq uitous and universal consequence of life under aerobic conditions.
