The main parameters of the antioxidant system in blood of male and female rabbits in age dynamics

Antioxidant system (AOS) is the most important unit of the general biological defense system. In assessing its state the choice of adequate, stable and sensitive indicators is important to determine the products of lipid peroxidation (LPO) and antioxidant defense enzyme complex. Antioxidant Index (AOI) is based on detecting blood and erythrocyte lipid peroxidation products such as malondialdehyde, diene conjugates of polyunsaturated fatty acids, and assessing the activity of antioxidant enzymes (i.e. superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase) in erythrocyte membranes. The aim of this work was to evaluate the role of AOS in the mechanism of blood oxidative homeostasis in Soviet Chinchilla rabbits (males and females) during different periods of ontogeny. Studies were performed in bioclinic on 10 rabbits. Blood was sampled from animals at the age of 60, 120 and 180 days. In the blood plasma we determined the content of diene conjugates and malondialdehyde, antioxidants and low molecular weight α-tocopherol and retinol. In hemolysates the activity of antioxidant enzymes, i.e. glutathione reductase, glutathione peroxidase, catalase, superoxide dismutase, was evaluated. For the first time for the biological evaluation of antioxidant system of rabbits a combined integrated AOI was used, which allows to reveal not only changes in the AOS of blood, but also to determine the proportion of its individual factors in the ontogenesis of rabbits. A comparison of the content of cholesterol, glucose and triglycerides in blood plasma showed the differences between male and female rabbits in lipid and energy metabolism. At the age of 180 days an increase in cholesterol, triglycerides and glucose in males was 11.6 %, 27.2 % (P ≤ 0.001) and 12.9 % (P ≤ 0.01), respectively, and in the females it was 14.7 %, 27.4 % (P ≤ 0.001) and 13.0 % (P ≤ 0.05), respectively. At the age of 120 and 180 days in the animals an insignificant reduction in all indicators was observed compared with the values obtained in the 60 day old rabbits. α-Tocopherol content in males aged 120 and 180 days increased by 14.4 and 21.9 %, respectively, and the retinol level was 8.3 and 29.2 % higher compared to the initial (day 60) values. In females there was a significant increase in the concentration of a-tocopherol by 14.9 and 18.9 %, respectively, and in retinol by 13.6 and 50.0 %, respectively, at days 120 and 180. Revealed changes in the overall and partial AOI in ontogeny indicate the initial activation of compensatory mechanism of antixidation in early ontogenesis and further decrease in a compensatory capacity of the antioxidant defense system in blood. Thus, the general index of the AOI in 4 month old rabbit males and females increased by 12-20 % and 4-12 %, respectively. A positive index value indicates the relatively high antioxidant protection despite the trend to reducing activity of the enzyme protection. In the 6 month old animals the integrated combined AOI values were negative, being typical for the state of oxidative stress. In males these changes were more evident and reliable. Usage of AOI index may be informative in assessment of the state of protective systems both in farm and laboratory animals