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：2020
卷号：66
期号：1
页码：54-59
DOI：10.3177/jnsv.66.54
出版社：Center for Academic Publications Japan
摘要：The indicator amino acid oxidation (IAAO) method is a novel method for determining protein requirements. Recently, the protein requirement of healthy young men was reevaluated using this method, and the currently recommended protein requirement based on nitrogen balance study was found to be deficient. Similarly, with respect to experimental animals, the protein concentration used widely in the experimental diets was assumed to be deficient. However, only a few studies have tested the IAAO method in experimental animals. In particular, there are no studies on the protein requirement of adult rats measured using this method. Therefore, we applied the IAAO method to adult rats, to determine their casein protein requirement. Male Wistar/ST rats (15-18 wk old, housed in lighting (lights on from 23:00 to 11:00) conditions) were provided with the test diet including graded casein (5, 7, 9, 13, 17, 21 and 25%) every 2 h from 11:00 to 17:00. Tracer administration of 13 C-phenylalanine was performed hourly from 14:00 to 17:00. Breath 13 CO 2 was measured every 30 min after the first tracer administration. There were significant differences between the 13 CO 2 concentration of the 5% and 17% casein groups at 17:00 and 18:00 ( p <0.05). The mean casein protein requirement and recommended dietary allowance (RDA) were estimated to be 5.2 g/kg BW/d and 7.0 g/kg BW/d using the mixed-effect change point regression model, respectively. Our results indicated that the recommended casein value may be slightly deficient to satisfy the protein metabolic demand of some adult rats..
关键词：IAAO method;metabolic demand;stable isotope;casein;adult rat
