Selenium: metabolism and endocrines (Minireview).
Selenium occurs both in prokaryocytes and eukaryocytes as a component of selenoenzymes or selenoproteins. Approximately 80 % of selenium in animal or human body occurs in the form of seleno-L-cysteine, an amino acid encoded by one of standard termination codons. Selenium is an integral component of the active site of glutathione peroxidases which plays an important role in the antioxidant system. Iodothyronine 5-deiodinase, type I is also a selenoenzyme consisting of two identical subunits which catalyzes a reductive monodeiodination of iodothyronine residues of the phenolic ring. General characteristics of several selenoproteins and selenium binding proteins are summarized, also certain facts on the effects of selenium deficiency in man and its distribution and toxicity in higher organisms, are reviewed. Selenium status in the population from selected regions in Slovakia is reported and compared with that in other countries.
Brtkova
A
Research Institute of Nutrition, SK-83337 Bratislava, Slovak Republic.
Brtko
J