The rabbit breeding is perspective industry of agriculture, that provides a  population with dietary meat. In terms of highly-intensity industrial technology of the industry it is almost impossible to avoid the influence of stress factors such as weaning, changing the type of feeding. In the pathogenesis of stress is hyper production of reactive oxygen species (ROS) bioenergetic and neurochemical systems of the brain. Brain ranks first among the tissues by the number of oxygen consumed per unit of weight; this level is so great that superoxide radical transformation is only 0.1% of metabolized neurons of oxygen may be toxic to it. Thus, the antioxidant system of the brain has a relatively small margin and deficiency of it’s components is very dangerous for the functional activity of neurons.

Of particular importance in antioxidant protection belongs to glutathione antioxidant system. The components of this system are glutathione metabolic and enzymatic link, namely, glutathione peroxidase (GPO), glutathione transferase (GT) and glutathione reductase (GR). The reduced form of glutathione (SH) with NADP ∙ H influenced GPO reacts with free radicals and inactivates the toxic effects of free radicals due to oxidation of glutathione. Restored oxidized glutathione under the influence of GH, which is induced by conditions of oxidative stress.

Correction enzymatic activity glutathione dependent system opens up new perspectives in solving problems of increasing adaptive and compensatory capacity of the organism, restore homeostasis in vital biochemical systems in terms of pathology, expanding the boundaries of the adequacy of the perception of a factor adverse effects on the body. The objective of the work - to study changes in the activity of glutathione peroxidase, glutathione reductase, glutathione-S-transferase and glutathione levels in brain tissues of rabbits of New Zealand breed in different age periods. The study found that the highest glutathione content in brain tissues of rabbits was 75 days age – 1,99±0,01 mmol/g. Glutathione is the main component parts of glutathione antioxidant system, which quickly mobilized with increasing content of peroxides and restores them in response, accompanied by the formation of oxidized glutathione (GSSG), which is toxic to cells. The content of GSH in the middle of the cell depends on the speed of balancing opposing processes such as de novo synthesis involving γ-glutamyl-cysteine synthetase and output in the extracellular space and regeneration through restoration and use of GSSG in neutralizing H₂O₂. Glutathione restores H₂O₂ to water and organic hydroperoxides - to hydrocompounds and interrupts the chain of intracellular reoxidation reactions. The high level of activity GPO is possible only on condition of maintaining a sufficiently high level of intracellular GSH, which not only serves as a substrate reactions, but also a factor necessary for the permanent restoration placed in the catalytic center of the enzyme selenium groups in the oxidized glutathione peroxidase reaction. GPO activity in brain tissues of rabbits decreased in 15- and 30-day age. It is possible that a gradual decrease glutathione peroxidase activity in this period is due to the exhaustion of the available pool of GSH and the accumulation of lipid peroxidation products. Starting from the 45th day GPO increased activity in the 90-day age was almost reached baseline.

Decreasing the activity of glutathione reductase in the 90 days age almost 5 times compared with those one days old rabbits. The most likely cause of reduced activity of the enzyme with age is the lack of regeneration of NADP pentose phosphate pathway in glucose oxidation. Normal functioning of the cell NADP∙ H -dependent glutathione reductase is essential to prevent oxidative damage to mitochondria that are unable to synthesize glutathione de novo and therefore depend on the intensity of oxidized glutathione glutathione reductase recovery and its income from the cytosol through the outer mitochondrial membrane.

Glutathione transferase activities marked increase throughout the study period. The 45-day age GT activity increased
1.6 times, and the 90-day at almost 2.4 times. Increase of enzymatic activity of GT can testify activation processes of neutralization products of lipid peroxidation and is a compensatory process aimed at inactivation of endogenous metabolites nature. Glutathionetransferase using GSN that prevents toxic action of radical oxygen species and electrophilic metabolites provides a significant portion of conjugation reactions. According to the research data were obtained from the dynamic changes of basic components of glutathione links antioxidant in the body of the New Zealand breed rabbits of all ages. It is noted increased activity of glutathione-S-transferase 2.4 times, while glutathione reductase activity decreased. The results demonstrate that the enzymatic link of glutathione system is directly involved in shaping the adaptive response of the body to the action of various stress factors. Correction of enzymatic activity dependent glutathione system opens up new perspectives in solving problems of increasing adaptive and compensatory capacity of the organism, restore homeostasis in vital biochemical systems under stress, expanding the boundaries of the adequacy of the perception of a factor adverse effects on the body. Investigation of the role of glutathione in the biochemical mechanisms of pathology will identify areas of search for new means of regulating levels of glutathione and on this basis to increase the effectiveness of industrial growing rabbits.

Key words: antioxidant system, glutathione, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, brain, rabbits.