ACTIVITY OF ANTIOXIDANT SYSTEM AND GROWTH INTENSITY IN COMMON CARP AFTER FEEDING DIET WITH DIFFERENT CONTENTS OF COPPER AND ZINC

Copper and Zinc are essential for fishes elements with wide spectrum of biological activity, however their simultaneous influence on the activity of antioxidant system and carp growth in physiological and exces - sive concentrations demands further investigations. Actuality of following experiments is determined, inter alia, by species differences of susceptibility of fishes to increased content of trace elements in diet, organic and tis - sue peculiarities of their distribution in organism. This paper presents that at Copper concentration in mixed fodder equated to 1 MPL (maximum per - mitted level) it accumulates in the gills of carp in greater measure than in the liver and skeletal muscles. At the same time, Zinc accumulates equally in the gills, liver and skeletal muscles. At 2 MPLs in mixed fodder, Copper accumulates equally in all abovementioned tissues of carp, while Zinc accumulates preferably in the gills and liver, than in the skeletal muscles. At 1 MPL of Copper and Zinc in mixed fodder, activity of main antioxidant enzymes in the carp gills, liver and skeletal muscles is increasing against the decreasing of lipid peroxidation products level. At 2 MPL of Copper and Zinc in mixed fodder, level of lipid peroxidation products in the gills, liver and skeletal muscles of carp is conversely increasing. During the experiment (45 days), carps of control group increased their live weight 1.65 times, and carps of the 1 st and 2 nd experimental groups — 1.94 and 1.82 times, respectively.

The aim of our experiment was to research of the activity of main antioxidant enzymes in tis-sues of carp and growth intensity under different concentration of Copper and Zinc in mixed fodder.

Materials and methods
The experiment was conducted on three groups (4 fishes in each group) of two year old common carp (Cyprinus carpio L.) with average live weight 332 g. For 45 days carps were kept in pongs 0.04 sq hectares each.
Carps of control group were fed standard granulated mixed fodder (К 111-3/4) without inclusion of Copper and Zinc. Carps of the 1 st and 2 nd experimental groups were fed the same fodder with addition of sulfates of Copper and Zinc.
Concentration of Copper and Zinc in the mixed fodder for the 1 st experimental group achieved 1 MPL (8 and 100 mg/kg correspondingly), while for the 2 nd experimental group it achieved 2 MPL (16 and 200 mg/kg correspondingly). Sulfates of Copper and Zinc were added to the mixed fodder on its granulation. Standard mixed fodder and mixed fodder with heavy metals addition were fed daily to the carps in dosage 6 % of their live weight at 8 am.
In the end of experiment the carps were weighted, after that three carps from each group were slaughtered and samples of the gills, liver and skeletal muscles were taken for laboratory research. In mentioned tissues samples the activity of superoxide dismutase, glutathione peroxidase and catalase was estimated [11-13], as well as concentration of Copper, Zinc [14], primary and secondary lipid peroxidation products [15][16][17].
Results of investigations were processed statistically. Average magnitude (M), average error (±m) and probability of differences between two average magnitudes (P) were calculated. Difference between two average magnitudes was considered probable at P<0.05. For calculations the programs Origin 6.0, Excel (Microsoft, USA) were used.

Results and discussion
It was revealed, that at Copper concentration in mixed fodder equated to 1 MPL in comparison to its natural content, it accumulates in the gills in greater extent (P<0.01) than in the liver and skeletal muscles (P<0.05). Zinc at concentration in the mixed fodder equated to 1 MPL accumulates equally in the gills, liver and skeletal muscles (P<0.05). At 2 MPL in the mixed fodder, Copper accumulates in all investigated tissues of carp in the same extent (P<0.05), while Zinc accumulates foremost in the gills and liver (P<0.01), and secondarily -in the skeletal muscles (P<0.05) ( Table 1).
Increasing of Copper and Zinc concentration in carp tissues led to changes of the activity  Table 2).
In particular, at 1 MPL of Copper and Zinc in the mixed fodder, the activity of superoxide dismutase and catalase increased in gills, while in the liver and skeletal muscles, increase of the activity of superoxide dismutase, glutathione peroxidase and catalase was observed (P<0.05-0.01).
Mentioned results suggested about activation of the activity of antioxidant enzymes at 1 MPL of Copper and Zinc in diet. Table 2 presents that at 2 MPL of Copper and Zinc in the mixed fodder the activity of superoxide dismutase and glutathione peroxidase is decreased in carp gills, liver and skeletal muscles, while the activity of catalase in mentioned tissues is increased (P<0.05). Apparently, relatively high concentrations of Copper and Zinc in diet lead to inhibition of the activity of the main antioxidant enzymes.
The observed changes of the antioxidant enzymes activity led to change of the content of primary and secondary lipid peroxidation products (lipid hydroperoxides, conjugated dienes and malondialdehyde) in the gills, liver and skeletal muscles. In particular, at 1 MPL of Copper and Zinc in mixed fodder, concentration of lipid hydroperoxides, conjugated dienes and malondialdehyde in the gills is decreasing. Content of lipid hydroperoxides and malondialdehyde is decreasing in the liver and skeletal muscles (P<0.05-0.01) ( Table 3). At 2 MPL of Copper and Zinc in diet, concentration of lipid hydroperoxides and malondialdehyde is increasing in the gills, and concentration of lipid hydroperoxides, conjugated dienes and malondialdehyde is decreasing in the liver and skeletal muscles (P<0.05).
Changes of the activity of main antioxidant enzymes, as well as alterations of content of Copper, Zinc and lipid peroxidation products in tissues were accompanied by changes of carp live weight in the end of the experiment ( Table 4). For instance, during the experiment carps of control group increased their live weight 1.65 times, while carps of the 1 st and the 2 nd experimental groups -1.94 and 1.82 times, respectively. The results are pointed on growth inhibition in carp under high (2 MPL) doses of Copper and Zinc in diet.

Conclusions
At Copper concentration in mixed fodder equated to 1 MPL in comparison to its natural content, it accumulates in the gills in greater extent, than in the liver and skeletal muscles. Zinc (at concentration in the mixed fodder equated to 1 MPL) accumulates equally in the gills, liver and skeletal muscles (P<0.05). At 2 MPL in the mixed fodder, Copper accumulates in all investigated tissues of carp in the same extent, while Zinc accumulates foremost in the gills and liver (P<0.01), and secondarily -in the skeletal muscles.
At 1 MPL of Copper and Zinc in the mixed fodder, the activity of superoxide dismutase and catalase was increased in gills, while in the liver and skeletal muscles increasing of the activity of superoxide dismutase, glutathione peroxidase and catalase was observed. At 2 MPL of Copper and Zinc in the mixed fodder, the activity of superoxide dismutase and glutathione peroxidase is decreased in carp gills, liver and skeletal muscles, while the activity of catalase in mentioned tissues is increased.
At 1 MPL of Copper and Zinc in mixed fodder, concentration of lipid hydroperoxides, conjugated dienes and malondialdehyde is decreased in the gills, and content of lipid hydroperoxides and malondialdehyde is decreased in the liver and skeletal muscles. At 2 MPL of Copper and Zinc in diet, concentration of lipid hydroperoxides and malondialdehyde is increased in the gills, and concentration of lipid hydroperoxides, conjugated dienes and malondialdehyde is decreased in the liver and skeletal muscles.
During the experiment (45 days) carps of control group increased their live weight 1.65 times, while carps of the 1 st and 2 nd experimental groups -1.94 and 1.82 times, respectively.
Perspectives for further research. The presented results are the part of complex investigation, dedicated to research of Copper and Zinc