Holben D H, Smith A M
Department of Human Nutrition and Food Management, Ohio State University, Columbus 43210, USA.
J Am Diet Assoc. 1999 Jul;99(7):836-43. doi: 10.1016/S0002-8223(99)00198-4.
Selenium functions within mammalian systems primarily in the form of selenoproteins. Selenoproteins contain selenium as selenocysteine and perform a variety of physiological roles. Eleven selenoproteins have been identified: cellular or classical glutathione peroxidase; plasma (or extracellular) glutathione peroxidase; phospholipid hydroperoxide glutathione peroxidase; gastrointestinal glutathione peroxidase; selenoprotein P; types 1, 2, and 3 iodothyronine deiodinase; selenoprotein W; thioredoxin reductase; and selenophosphate synthetase. Of these, cellular and plasma glutathione peroxidase are the functional parameters used for the assessment of selenium status. Glutathione peroxidases catalyze the reduction of peroxides that can cause cellular damage. Thioredoxin reductase provides reducing power for several biochemical processes and defends against oxidative stress. Selenoprotein P appears to play a role in oxidant defense. Selenoprotein W may play a role in oxidant defense and be involved with muscle metabolism. Thyroid deiodinases function in the formation and regulation of active thyroid hormone. Selenophosphate synthetase is an enzyme required for the incorporation of selenocysteine into selenoproteins. In addition, a protein in the sperm mitochondrial capsule, which is vital to the integrity of sperm flagella, may be a unique selenoprotein. Recommended intakes, food sources, and status assessment of selenium, as well as selenium's role in health and disease processes, are reviewed.
硒在哺乳动物系统中主要以硒蛋白的形式发挥作用。硒蛋白含有作为硒代半胱氨酸的硒，并发挥多种生理作用。已鉴定出11种硒蛋白：细胞型或经典型谷胱甘肽过氧化物酶；血浆（或细胞外）谷胱甘肽过氧化物酶；磷脂氢过氧化物谷胱甘肽过氧化物酶；胃肠道谷胱甘肽过氧化物酶；硒蛋白P；1型、2型和3型碘甲状腺原氨酸脱碘酶；硒蛋白W；硫氧还蛋白还原酶；以及硒磷酸合成酶。其中，细胞型和血浆谷胱甘肽过氧化物酶是用于评估硒状态的功能参数。谷胱甘肽过氧化物酶催化可导致细胞损伤的过氧化物的还原。硫氧还蛋白还原酶为多个生化过程提供还原力，并抵御氧化应激。硒蛋白P似乎在抗氧化防御中发挥作用。硒蛋白W可能在抗氧化防御中发挥作用，并参与肌肉代谢。甲状腺脱碘酶在活性甲状腺激素的形成和调节中起作用。硒磷酸合成酶是将硒代半胱氨酸掺入硒蛋白所需的一种酶。此外，精子线粒体膜中的一种对精子鞭毛完整性至关重要的蛋白质可能是一种独特的硒蛋白。本文综述了硒的推荐摄入量、食物来源、状态评估以及硒在健康和疾病过程中的作用。
