Effect of dietary methionine on tissue selenium and glutathione peroxidase (EC 1.11.1.9) activity in rats given selenomethionine.
Effect of dietary methionine on tissue selenium and glutathione peroxidase (EC 1.11.1.9) activity in rats given selenomethionine.
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膳食蛋氨酸对给予硒代蛋氨酸的大鼠组织硒和谷胱甘肽过氧化物酶 (EC 1.11.1.9) 活性的影响。
DOI：
10.1079/bjn19880076
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Sunde,RA
中科院分区：
文献类型：
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作者：
Waschulewski,IH;Sunde,RA
1. 1.11.1.9以雄性断乳大鼠为研究对象，研究了日粮蛋氨酸对硒蛋氨酸（[Se]Met）利用率、组织硒沉积和谷胱甘肽过氧化物酶（GSH-Px）合成的影响.当大鼠给予0.5毫克硒[硒]蛋氨酸/公斤的饮食补充0，4或9克蛋氨酸/公斤，硒在血浆中，红细胞，肝脏和肌肉显着增加超过20天的时间为所有蛋氨酸治疗组。而红细胞硒和肌肉硒的增加量，在蛋氨酸缺乏组显著高于蛋氨酸补充组.与组织硒的增加相反，蛋氨酸缺乏大鼠肝脏、血浆和肌肉中GSH-Px活性降低，而补充蛋氨酸大鼠GSH-Px活性保持或增加.从测定的硒浓度和GSH-Px活性计算与GSH-Px相关的组织硒的百分比。与补充蛋氨酸的大鼠相比，蛋氨酸缺乏的大鼠中硒与GSH-Px的百分比显著降低.这些结果表明，当蛋氨酸在饮食中受到限制时，来自饮食[Se]Met的Se优先并入身体蛋白质中，而不是用于GSH-Px合成。这些结果进一步表明，[Se]Met可能不是用于硒补充的最佳硒化合物，因为当[Se] Met在低蛋氨酸的饮食中提供时，饮食[Se]Met代谢为生物化学活性形式（如GSH-Px）受损。
1. The effect of dietary methionine on the utilization of selenium from dietary selenomethionine ([Se]Met) for tissue Se deposition and for glutathione peroxidase (EC 1.11.1.9; GSH-Px) synthesis was studied in male weanling rats.2. When rats were given 0.5 mg Se as [Se]Met/kg diet supplemented with 0, 4 or 9 g methionine/kg, Se in plasma, erythrocytes, liver and muscle increased significantly over the 20 d period for all methionine-treatment groups. The increases in erythrocyte and muscle Se, however, were significantly higher in rats fed on the methionine-deficient diet compared with the methionine-supplemented diets.3. In contrast to the increases in tissue Se, GSH-Px activity in liver, plasma and muscle decreased in methionine-deficient rats given 0.5 mg Se as [Se]Met/kg whereas GSH-Px activity was maintained or increased in rats supplemented with methionine.4. The percentage of tissue Se associated with GSH-Px was calculated from the measured Se concentration and GSH-Px activity. A significantly lower percentage of Se was associated with GSH-Px in methionine-deficient rats compared with methionine-supplemented rats.5. These results show that Se from dietary [Se]Met is preferentially incorporated into body proteins rather than used for GSH-Px synthesis when methionine is limiting in the diet.6. These results further suggest that [Se]Met might not be the optimum Se compound to use for Se supplementation because metabolism of dietary [Se]Met to a biochemically active form, such as GSH-Px, was impaired when [Se]Met was provided in diets low in methionine.