Hidiroglou M, Zarkadas C G
Can J Physiol Pharmacol. 1976 Jun;54(3):336-46. doi: 10.1139/y76-048.
Two groups of sheep fed a diet of hay known to produce nutritional muscular dystrophy, one group of which received selenium supplementation, were used to study the effects of selenium on the metabolism of administered L-(35S) methionine by rumen microflora. Rumen bacterial proteins of the Se supplemented sheep contained significantly higher levels of radiosulfur than the bacterial protein of the non-supplemented sheep. Of hte L-(35S) methionine present in the rumen liquor samples from Se-supplemented sheep 2 h after administration, 13.3% of the amino acid, which was measured as methionine sulfone, was found in the microbial proteins. A large proportion of the administered labeled methionine was resynthesized as cyst(e)ine which may account in part for that determined as cysteic acid in rumen bacterial and plasma proteins. The observed low levels of radiosulfur found in rumen microflora from selenium deficient wethers, indicates that the presence of selenium profoundly affects the rate of methionine metabolism and the distribution of methionine in rumen bacterial and protozoal proteins. In another experiment, the effect of selenium on the metabolism of L-(Me-3H) methionine was studied. The selenium status of the sheep had no significant effect (P greater than 0.05) on the distribution of 35S radioactivity in the blood plasma and tissues.
两组绵羊被饲喂已知会导致营养性肌肉萎缩的干草日粮，其中一组补充了硒，以此来研究硒对瘤胃微生物群对所施用的L-(35S)蛋氨酸代谢的影响。补充硒的绵羊的瘤胃细菌蛋白质所含的放射性硫水平显著高于未补充硒的绵羊的细菌蛋白质。在给补充硒的绵羊施用L-(35S)蛋氨酸2小时后，瘤胃液样本中存在的该氨基酸中有13.3%（以甲硫氨酸砜形式测定）在微生物蛋白质中被发现。大部分施用的标记蛋氨酸被重新合成为半胱氨酸（或胱氨酸），这可能部分解释了在瘤胃细菌和血浆蛋白质中被测定为半胱氨酸的情况。在缺硒阉羊的瘤胃微生物群中观察到的低水平放射性硫表明，硒的存在深刻影响蛋氨酸的代谢速率以及蛋氨酸在瘤胃细菌和原生动物蛋白质中的分布。在另一项实验中，研究了硒对L-(甲基-3H)蛋氨酸代谢的影响。绵羊的硒状态对血浆和组织中35S放射性的分布没有显著影响（P大于0.05）。
