Untitled

Abstract

In aerobic organisms, oxygen is essential for sufficient energy production but self-contradictory, produces chronic toxic stress in cells. So, protective techniques must exist for removal of toxic free radicals which are byproducts of oxygen. Diverse protective systems have evolved to enable adaptation of antioxidant activity. Tissues and organs have different rates of metabolic activity and oxygen consumption. Their levels of antioxidants are also different. Such is the case with glutathione (GSH) and cysteine, which are lower in the brain than the liver, kidney, or muscle. Investigations of oxidative responses in different complex organisms such as mammals, organs, and tissues which contain distinct antioxidant systems and this may form the basis for differential susceptibility to toxic agents. Notable advances have been made in our understanding of these distinct systems, with several antioxidant systems and their regulatory pathways being described at the cellular level, thus understanding the pathways leading to the induction of antioxidant responses will enable development of strategies to protect against oxidative damage.