Apparent compartmentation of body nitrogen in one human subject: its consequences in measuring the rate of whole-body protein synthesis with 15N.
Apparent compartmentation of body nitrogen in one human subject: its consequences in measuring the rate of whole-body protein synthesis with 15N.
复制标题
一名受试者体内氮的明显区隔：其在测量 15N 全身蛋白质合成率时的影响。
作者：
Edward Fern;P. Garlick;J. Waterlow
在一名进食受试者中测量全身蛋白质合成速率，其中7种15N标记的氨基酸（静脉内和口服剂量）和2种15N蛋白质混合物（仅口服剂量）。在12小时的实验期内，分别从尿中氨和总尿素排泄率确定。除了口服甘氨酸和丙氨酸，氨和尿素的合成速率在每项研究中都有明显的不同，当计算时假设体内只有一个代谢氮库。一般来说，静脉注射示踪剂与尿素的比率较高，口服途径与氨的比率较高。通过计算氨和尿素流量的算术平均值或调和平均值的合成率，可以显著降低15 N静脉注射和口服剂量之间的差异。当假设两个池接收等量的示踪剂（算术）或两者具有相同的氮周转率（谐波）时，平均值对应于代谢氮两池模型中总通量的估计值。通过这样减少体内氮的物理分离的影响，可以检查示踪剂的区室化的代谢方面。结果表明，蛋白质合成的绝对值取决于标记氮的来源。数据在此实证背景下进行了讨论。
The rate of protein synthesis in the whole body was measured in one fed subject with seven 15N-labelled amino acids (intravenous and oral doses) and two 15N protein mixtures (oral doses only). The rates were determined individually from the urinary excretion of ammonia and total urea over a 12 h experimental period. Except with oral glycine and alanine, the synthesis rates given by ammonia and urea were appreciably different within each study when calculated on the assumption of a single pool of metabolic nitrogen in the body. In general, intravenous administration of the tracers gave higher rates with urea and the oral route gave higher rates with ammonia. The differences between intravenous and oral doses of 15N could be reduced significantly by calculating synthesis rates from either the arithmetic or harmonic average of flux rates given by ammonia and urea. The averages correspond to estimates of the total flux in a two-pool model of metabolic nitrogen when it is assumed either that both pools receive an equal amount of tracer (arithmetic) or that both have the same rate of nitrogen turnover (harmonic). By so reducing the effect of physical separation of nitrogen in the body, the metabolic aspects of compartmentation of the tracer could be examined. The results show that the absolute value obtained for protein synthesis depends on the source of labelled nitrogen. The data are discussed in this empirical context.
全身亮氨酸和赖氨酸代谢：年轻男性对膳食蛋白质摄入量的反应。
DOI：
10.1152/ajpendo.1981.240.6.e712
发表时间：
1981
期刊：
The American journal of physiology
影响因子：
--
作者：
Motil,KJ;Matthews,DE;Bier,DM;Burke,JF;Munro,HN;Young,VR
通讯作者：
Young,VR