I. A. Zaitseva

В ходе работы проанализированы концентрации ртути (Hg) у млекопитающих с разной эколого-трофической специализацией, обитающих в Республике Карелия. Объектами служили 18 видов из отрядов Carnivora, Artiodactyla, Eulipotyphla и Rodentia. Содержание общей Hg в печени, почке и скелетной мышце животных определяли методом прямого пиролитического разложения с атомно-абсорбционной детекцией. Выявленные особенности уровня Hg у исследованных животных согласовывались с хорошо известными закономерностями распределения металла как между органами у отдельных видов, так и в пределах уровня консументов в пищевых цепях. Почти у всех видов животных содержание Hg было максимальным в почке, реже в печени. Вне зависимости от образа жизни (наземного или полуводного) консументы второго порядка (плотоядные виды) характеризовались более высоким содержанием Hg в организме по сравнению с консументами первого порядка (питающимися преимущественно растительной пищей). Концентрации Hg в организме животных Карелии в основном не достигали летальных значений и не превышали норм, зафиксированных для тех же или таксономически близких видов из других регионов России и стран мира. Результаты исследования свидетельствуют об относительно низком уровне Hg в организме млекопитающих наземных и полуводных экосистем Карелии. The study analyzed mercury (Hg) concentrations in mammals with different ecological and trophic specializations living in the Republic of Karelia. The subjects of this study comprised 18 species from the orders Carnivora, Artiodactyla, Eulipotyphla, and Rodentia. The total Hg content in the liver, kidney, and skeletal muscle of the animals was determined by direct pyrolytic decomposition with atomic absorption detection. The identified features of Hg levels in the studied animals were consistent with well-known patterns of metal distribution both between organs in individual species and within the level of consumers in food chains. In the majority of animal species examined, the kidneys were found to contain the highest concentrations of Hg, with the liver exhibiting a lower but still significant level of accumulation. Notwithstanding the subject's lifestyle (terrestrial or semi-aquatic), second-order consumers (carnivorous species) were distinguished by elevated Hg levels in the body in comparison to first-order consumers (species that primarily consume plant-based foods). The concentrations of Hg in the bodies of animals in Karelia did not generally reach lethal levels and did not exceed the established norms for the same or taxonomically closely related species from other regions of Russia and countries around the world. The findings of the study suggest that the level of Hg in the bodies of mammals inhabiting terrestrial and semi-aquatic ecosystems in Karelia is relatively low.

The content of vitamins in the body is one of the most important indicators reflecting the level of nutrition of large ungulate mammals living on the northern periphery of their range in conditions of limited access to food resources in the cold period of the year. In this work, the content of retinol (vitamin A) and α-tocopherol (vitamin E) in the organs and tissues of wild moose ( Alces alces ) of different ages and sexes, as well as European red deer ( Cervus elaphus ) and maral ( C. e. sibiricus ) kept in semi-free conditions in the Northwest of Russia (Republic of Karelia and Leningrad Region) was studied. Biological material was collected from animals harvested because of legal hunting during the hunting season from October to January. The level of vitamins in the studied animals was generally consistent with the values established for cervids living in other regions of the world, including those with a milder climate. Relatively low vitamin content identified in species of the genus Cervus warrants further investigation. In moose, no sex- or age-related differences were found in the content of vitamins A and E, except for a lower level of α-tocopherol in the kidneys of adult females compared to young ones. Pregnant females had a comparatively low retinol content in the examined organs and tissues. The effect of the region in which the moose were hunted on the content of retinol in the liver and α-tocopherol in the heart was found, which may be due to the natural and climatic features of the study areas, which determine the composition of phytocenoses and the forage nutritive value. The results obtained can be used to assess the status of large ungulates and their population level management plans.

One of the reasons for the physiological and biochemical changes in the body of animals that occur as a result of selection for a defensive reaction toward humans is the activity of the hypothalamic-pituitary-adrenal system. An aggressive response, raising the level of stress in the body, contributes to the disruption of redox balance. However, data on the content of the main natural antioxidant vitamin E in mammals undergoing selection for behavior are limited. This study was designed to determine the content of α-tocopherol in American mink selected to eliminate (“domestic” or tame) or promote (aggressive) defensive reactions toward humans for 22–23 generations. We studied 4 groups (n = 10 in each) of 11-month-old male standard dark brown mink with varying degrees of aggressive (groups –2, –3) or tame (groups +3, +6) behavior. The content of α-tocopherol in the blood serum, liver, kidneys, heart, skeletal muscle, spleen was determined by HPLC. Aggressive mink have lower levels of α-tocopherol in the blood serum and liver, which reflect the status of vitamin E in the body. In most cases, differences were found between mink of the most aggressive and the most “domestic” groups. These results can be associated with features of the neuroendocrine system responsible for aggressive behavior, which affect the processes of metabolism and depletion of α-tocopherol in the body.

We studied the vitamins A (retinol) and E (α-tocopherol) content in the tissues of the bank vole (Myodes (Clethrionomys) glareolus) and common shrew (Sorex araneus) inhabiting the northern periphery of its range. The distribution of vitamin A in the common shrew and bank vole tissues was similar, the highest content was found in the liver, and the lowest level was in the heart. Agerelated differences in retinol content were detected in the kidneys of two species, as well as in the skeletal muscle of the shrew. Significantly lower vitamin E content was found in all organs of young shrews before wintering, compared to adult wintered animals, while in the bank vole no such age-related differences were found. Interspecies differences in the levels of vitamins A and E in the liver of overwintered animals were revealed. The results obtained show that vitamins A and E content in the tissues of the bank vole and the common shrew is determined by the metabolic processes and the ecological characteristics of the species. The vitamins level in the common shrew depends largely on age.

We have studied the concentration of vitamins A (retinol) and E (α-tocopherol) in the tissues of the bank vole (Myodes (Clethrionomys) glareolus) and common shrew (Sorex araneus) inhabiting the northern periphery of its natural habitat. The distribution of vitamin A in the common shrew and bank vole tissues is similar: the highest concentration is found in the liver, and the lowest level is found in the heart. Age-related differences in the retinol concentration are detected in the kidneys of the two species, as well as in the skeletal muscle of the shrew. A significantly lower vitamin E concentration is found in all organs of young shrews before wintering, compared to adult overwintered animals, while in the bank vole no such age-related differences are found. Interspecies differences in the levels of vitamins A and E in the liver of overwintered animals are revealed. The results obtained show that the concentration of vitamins A and E in the tissues of the bank vole and the common shrew is determined by metabolic processes and the ecological characteristics of the species. The level of vitamins in the common shrew depends largely on age.