Selenium (Se) in the blood (chromatography)
It is ultimate trace mineral being the essential component of antioxidant and other cellular enzymes with toxic properties when taken in high doses. Selenium is a key component of several vital selenoproteins and enzymes. For instance, antioxidant glutathione peroxidase neutralizes free radicals and peroxidized lipids, protects the cell from damaging effects on the membranes structure and function. Cell antioxidant enzymes prevent oxidative stress contributing many diseases development. Selenoproteins are involved in the thyroid function regulation. Selenium is important for the entire immune system operation as well as for reproductive functions. The significance of this micronutrient in line to prevent cancer has been pointed out in various studies. It is an arsenic antagonist, protects the body from the cadmium, lead, thallium, mercury effects.
Selenium comes the human body with food and drinking water; recommended daily dose is 50-70 mcg. The main sources are many plant and animal products, fish and seafood. Selenium deficiency can be observed when it is supplied with food and water insufficiently, when digestion and absorption processes are disturbed (for example, malabsorption syndrome, 20% of population after bariatric surgery), with complete parenteral nutrition, as well as with increased selenium consumption or metabolism violation.
Significant selenium deficiency in blood plasma with concentration less than 20 μg / l can cause progressive myocardial damage - Keshan's disease (endemic cardiomyopathy). Nonspecific resistance of the body (resistance to any pathogenic effects) decreases, male reproductive function is impaired, and risk of cancer increases when concentration is less than 50 μg / L. Lack of selenium can cause the decrease in the child’s growth rate due to triiodothyronine-controlled synthesis decrease of growth hormone in pituitary gland. Simultaneous deficiency of selenium and iodine cause the hypothyroidism represented in myxedema in adults and growth retardation and impaired mental development in children. Selenium deficiency can follow the cystic fibrosis of pancreas, bronchial asthma, cardiovascular diseases and number of other pathological conditions. Insufficient intake of selenium and other microelements is taken as an etiological factor of Kashin-Beck disease (Urovsky disease) - osteoarthritis with multiple joint deformities and bone growth disorders.
In large doses, selenium causes poisoning - selenium. For humans, the toxic dose of selenium is 5 mg. Selenotoxicosis can occur with excessive use of containing selenium food additives or when operating the in foundries, electronic, copper smelting, oil refining, chemical industries. Selenium is produced as copper by-product in the industry. It is used in electronic semiconductors, as decolorizing agent for ceramics and glass, and vulcanizing agent for tire production. Intoxication is presented with garlic taste (related to dimethyl selenide formation), nausea, hair loss, brittle nails, dermatitis, nervous system damage in the form of numbness, convulsions or paralysis of the limbs, possible psycho-emotional disorders.