The Content of Retinol, α-Tocopherol and Glutathione in Tissues of the Wild Boar (Sus scrofa L.) Inhabiting the Northwest of Russia

Phenotypic plasticity and resistance to climatic conditions allowed the wild boar Sus scrofa L. to expand its historical range and move away its Northern border. For the adaptation to living at the periphery of its range under severe conditions of the North, the status of vitamins A and E, which are natural antioxidants critical for growth, reproduction and immunity maintenance, is of vital importance. The aim of this work was to investigate the content of retinol, α-tocopherol, and the low-molecular-weight antioxidant glutathione (GSH) in the liver, kidney, heart, skeletal muscle, lungs, and spleen of the wild boars ( n = 65) aged 0.5–8 years, living in the Northwest of Russia. Our results indicate that the studied animals practically did not differ in the retinol content from their counterparts living in the Central and Southern Europe, but had lower tissue α-tocopherol levels, which is probably due to the limited food resources and harsh climatic conditions of the cold season in the North. Vitamin and GSH levels in most tissues were comparable in piglets and adult animals. With age, retinol and α-tocopherol accumulated in the liver and kidney, while α-tocopherol alone accumulated in the heart, which is typical for other mammalian species. An increase in the GSH level was found in the lungs of animals over 5 years of age. The revealed vitamin status, which was formed in the wild boar under conditions of the Russia’s Northwest, as well as the peculiarities of the age-related dynamics of the above indices, may serve a compelling evidence for the successful adaptation of this species to inhabiting the northern periphery of its range, as confirmed by the growth of its population.