In the review of the literature it was generalized the data due to the classification and characterization of antioxidant protection system of animals body. This model combines a number of different by its nature substances. Each of the components of the antioxidant system operates in close relationship with its other structural elements, harmoniously, and in many cases complements and in many cases - enhances the action of each other. Glutathione system forms functional basis of antioxidant defense system, constituent elements of which has its own glutathione and enzymes, which catalyze the reaction of its reverse transformation (oxidation ↔ recovery). Glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase are attributed to these enzymes.Most researchers conventionally distributed antioxidant defense system in enzyme and non-enzyme. Catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione transferase and other enzymes are included to enzymatic link of antioxidant defense system. Fat-soluble vitamins A, E and K, water-soluble vitamins C and PP, biogenic amines, glutathione, carotenoids, ubiquinone, sterols are included to non-enzyme system. As the enzyme, as non-enzyme antioxidant defense system is present in the bloodstream. The activity of enzymatic antioxidant system is well regulated and depends on the age of the animals, physiological condition, the dynamics of hormone, synthesis intensity of antioxidant enzyme, pH medium, the presence of coenzymes, inhibitors, activators, and other factors. Non-enzyme link of antioxidant system does not need so many regulators as the most chemical substance - antioxidant - enters into chemical reaction with the radical. The rate of reaction may be only changed.
