Stein T P, Settle R G, Albina J A, Dempsey D T, Melnick G
J Nutr. 1986 Sep;116(9):1651-9. doi: 10.1093/jn/116.9.1651.
Eight 15N-labeled nonessential amino acids plus 15NH4Cl were administered over a 10-h period to four healthy adult males using a primed-constant dosage regimen. The amount of 15N excreted in the urine and the urinary ammonia, hippuric acid and plasma alanine 15N enrichments were measured. There was a high degree of consistency across subjects in the ordering of the nine compounds based on the fraction of 15N excreted (Kendall coefficient of concordance W = 0.83, P less than 0.01). Protein synthesis rates were calculated from the urinary ammonia plateau enrichment and the cumulative excretion of 15N. Glycine was one of the few amino acids that gave similar values by both methods.
采用首剂-恒量给药方案，在10小时内给4名健康成年男性施用8种15N标记的非必需氨基酸加15NH4Cl。测定尿中排出的15N量以及尿氨、马尿酸和血浆丙氨酸的15N富集情况。基于15N排出分数，9种化合物在各受试者之间的排序具有高度一致性（肯德尔和谐系数W = 0.83，P < 0.01）。根据尿氨平台期富集情况和15N的累积排泄量计算蛋白质合成速率。甘氨酸是少数通过两种方法得出相似值的氨基酸之一。
