The Peculiarities of Selenium Metabolism in Organisms
Regina Firantienė, Juozapas Račkus, Sofija Sasnauskienė, Regina Emužytė, Danutė Kalibatienė, Valerija Jablonskienė
Summary
Dietary selenium is an essential micronutrient that affects various aspects of human health. The human organism supplementation with selenium are carried out by dietary. The amount of selenium in dietary depends on the selenium concentration in soil. The rec i ommended dietary allowance for selenium is 55 ^g/day for normal adult. Selenium is naturally occurring in some oxidative states. Inorganic selenium forms are incorporated into various organisms. It is demonstrated that selenium in nature can exist in two forms: selenomethionine and selenocysteine. Selenomethionine is found in plants and selenocysteine in animals and human organism. The incorporation of selenium into selenoproteins is connected with amino acid selenocysteine and then the selenoproteins are involved in physiological and biochemical functions, including immune responses. Selenium is essential component or cofactor of enzymes. It is also involved in other crucial cellular processes, including innate and adaptive immune responses. Selenium deficiency has been shown to result in loss robust immune responses to viruses, tumors, and allergens, composed to selenium adequate controls. There is considerable evidence that selenium affect different types of immune responses. Sel enium supplementation may enhance Th1- type immune responses to a greater extent than Th2-type responses. The sele- nium-supplementation shows benefit in the synthesis of antioxidant enzymes. The mechanisms by which selenium affects the immune system is less clear than how selenium affect the virus itself. There are no obvious immune-related diseases associated with selenium deficiency. It is supposed that selenium affects common immunity disorders such as allergic asthma, chronic inflammation, infectious diseases, and cancers.
Keywords: selenium, selenoprotein, metabolism, toxicity, immunity, virus, aging.
