期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：1976
卷号：22
期号：5
页码：397-403
DOI：10.3177/jnsv.22.397
出版社：Center for Academic Publications Japan
摘要：The object of this study was to determine the effects of individual amino acid supplements on the development of tyrosine toxicity in growing rats fed 10% casein containing 5% tyrosine. Each amino acid was added at levels equivalent to its content in 20% casein. Supplement of methionine to the high tyrosine diet partially alleviated both growth depression and pathological lesions. Threonine and cystine had a somewhat beneficial effect, but the single addition of other amino acids was not effective. Besides, some amino acids enhanced the severity of the toxicity even more. The effects of methionine supplementation were highest at 0.66 to 1.32 levels (equivalent to the methionine content in 20 to 40% casein). By the supplement of both 0.66 % methionine and 0.90% threonine to the high tyrosine diet, growth was significantly improved and toxic lesions were completely prevented. It was confirmed that the counteracting effects to the toxicity, caused by the extra addition of protein (casein) to rats fed a high tyrosine-low protein diet, were mainly attributed to the effectiveness of the methionine and threonine, i.e. , first-and second-limiting amino acids, respectively, contained in it.
