Smith A M, Picciano M F
J Nutr. 1987 Apr;117(4):725-31. doi: 10.1093/jn/117.4.725.
Bioavailability of the organic forms of selenium (Se), selenomethionine (Se-methionine) and Se-yeast was determined relative to that of an inorganic form, selenite, in the lactating rat. A purified, casein-based diet without added Se was fed to nine groups of rats throughout pregnancy to produce a marginal Se deficiency. During lactation, groups (n = 8) were fed experimental diets containing either 0.1, 0.25 or 0.5 ppm Se as selenite, Se-methionine, or Se-yeast. On d 18 of lactation, tissue Se and glutathione peroxidase (GSH-Px) activities of dams and pups were determined. Based on slope-ratio analyses, the bioavailability of Se-methionine and Se-yeast was greater than that of selenite in both lactating dams and their nursing pups. The greater availability of organic Se to pup tissues may be a direct result of the greater concentration of Se in the milk of dams fed organic Se. A dietary level of 0.25 ppm Se as Se-methionine ensured maximal GSH-Px activity in both dam and pup tissues, but 0.5 ppm Se was necessary when selenite or Se-yeast was fed. These results indicate that, regardless of form, the National Research Council recommendation for growing rats of 0.1 ppm Se is not adequate to replete lactating dams and maintain maximal tissue GSH-Px in nursing pups.
在泌乳大鼠中，测定了有机形式的硒（Se）、硒代蛋氨酸（Se-蛋氨酸）和富硒酵母相对于无机形式亚硒酸盐的生物利用度。在整个孕期，给九组大鼠喂食不含添加硒的纯化酪蛋白基日粮，以造成边缘性硒缺乏。在哺乳期，将每组（n = 8）大鼠分别喂食含0.1、0.25或0.5 ppm硒的实验日粮，硒的形式分别为亚硒酸盐、Se-蛋氨酸或富硒酵母。在哺乳期第18天，测定母鼠和幼鼠的组织硒含量及谷胱甘肽过氧化物酶（GSH-Px）活性。基于斜率比分析，在泌乳母鼠及其哺乳幼鼠中，Se-蛋氨酸和富硒酵母的生物利用度均高于亚硒酸盐。有机硒对幼鼠组织的更高利用率可能直接源于喂食有机硒的母鼠乳汁中硒浓度更高。日粮中Se-蛋氨酸的硒含量为0.25 ppm时可确保母鼠和幼鼠组织中的GSH-Px活性达到最高，但喂食亚硒酸盐或富硒酵母时则需要0.5 ppm的硒。这些结果表明，无论形式如何，美国国家研究委员会对生长大鼠0.1 ppm硒的推荐量不足以补充泌乳母鼠的硒含量并维持哺乳幼鼠组织中GSH-Px的最高活性。
