文章基本信息

标题：An Evaluation of Protein Intake for Metabolic Demands and the Quality of Dietary Protein in Rats Using an Indicator Amino Acid Oxidation Method
本地全文：下载
作者：Aki OGAWA ; Yuka NARUSE ; Yasutaka SHIGEMURA 等
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：2011
卷号：57
期号：6
页码：418-425
DOI：10.3177/jnsv.57.418
出版社：Center for Academic Publications Japan
摘要：Currently, protein requirements are generally determined based on nitrogen balance studies, but there are a variety of limitations associated with this method. The indicator amino acid oxidation (IAAO) method, with a theoretical base that differs widely from the nitrogen balance method, was developed as an alternative method for humans. The objective of the present study was to evaluate protein intakes for metabolic demands and protein quality, using protein itself, in rats employing the IAAO technique with L -[1-¹³C]phenylalanine. Male Wistar/ST rats (5-6 wk old) received a graded casein (4.3, 8.6, 12.9, 17.2, 21.5, 25.8%), or a wheat gluten (7.2, 10.8, 14.4, 18.0, 21.6, 25.2%) diet, along with L -[1-¹³C]phenylalanine. An isotopic plateau in breath was achieved 210 min after the start of the ¹³C ingestion. The protein intakes for metabolic demands were calculated by applying a mixed-effect change-point regression model to breath ¹³CO₂ data, which identified a breakpoint at minimal breath ¹³CO₂ in response to graded protein intake. The protein intakes for metabolic demands determined by the IAAO method were 13.1 g/kg BW/d for casein and 18.1 g/kg BW/d for wheat gluten, showing a tendency similar to that determined by the nitrogen balance method. These results demonstrated that the IAAO method could be employed to evaluate not only the protein intakes for metabolic demands, but the dietary protein quality in freely living rats, suggesting that this method might be viable in a clinical setting.
关键词：protein metabolic demand;protein quality;indicator amino acid oxidation;rats