ASSESSMENT OF THE CONTENT OF MALONDIALDEHYDE IN THE PLASMA AND ERYTHROCYTES OF BLOOD OF SHEEP UNDER CHRONIC INTAKE OF LEAD NITRATE WITH THE RATION

The article presents new experimental data on the content of malondialdehyde (MDA) in the plasma and erythrocytes of peripheral blood of sheep, which received lead nitrate in doses of 0.3, 1.5 and 9.0 mg • kg-1 body weight during the 90 days of the study with the main ration. The animals were divided into four groups: group 1 (control), the concentration of lead in the ration for animals of the 2nd group was 5 mg • kg-1 feed, the 3rd group – 25 mg • kg-1 feed, the 4th group – 150 mg • kg-1 feed, which corresponded to 1, 5 and 30 maximum permissible levels (MPL) of metal in the feed. The ration included 0.3 kg of mixed feed and 2 kg of mixed hay. Lead nitrate was added to the feed once a day, taking into account the amount of feed (on average 2 ±0,3 kg) entering the gastrointestinal tract. Thus, the daily intake of metal per head for sheep of the 2nd group was 10 mg, the 3rd group – 50 mg, the 4th group – 300 mg, and per kg of body weight – 0.3, 1.5 and 9,0 mg, respectively. Blood samples were taken from the jugular vein of sheep before feeding (initial data) and on the 7th, 14th, 28th, 42nd, 70th and 90th days of intoxication. During the study period, animals were slaughtered: before inoculating, 1 head from the 1st group; on the 30th and 60th days, 1 head from the 2nd group and 3 heads from the 3rd and 4th groups; on the 90th day, 3 heads from all groups. It was shown that changes in the content of MDA in plasma and erythrocytes of peripheral blood of sheep under exposed to lead at doses of 0.3, 1.5 and 9.0 mg • kg-1 body weight during 90 days of the study are nonlinear. With an increase in the dose of exposure, the most pronounced pattern of changes was observed. A comparative analysis of the MDA content in sheep plasma and erythrocytes revealed significant changes in cells, which is probably due to the specific distribution of lead in peripheral blood components. It is assumed that the revealed changes in the content of MDA depend not only on the concentration of lead in plasma and erythrocytes of peripheral blood of sheep, but also on the activity of antioxidants.