示踪亮氨酸在静脉输注状态下不同时间点上终产物的丰度变化及^(13)CO_2产生率分析  

End product enrichment changes of tracer leucine under the status of infusion and analysis on ^(13)CO_2 production rate

作　　者：姬一兵[1] 朴建华[1] 张宇辉[2] 勾凌燕[2] 徐忠华[2] 毛德倩[1] 李卫东[1] 杨晓光[1] 

机构地区：[1]中国疾病预防控制中心营养与食品安全所,北京100050 [2]中国人民解放军第四军医大学白求恩军医学院

出　　处：《卫生研究》2009年第3期363-366,共4页Journal of Hygiene Research

基　　金：达能膳食营养研究与宣教基金(No.DIC2006-07)

摘　　要：目的分析氨基酸代谢动力学研究中在持续静脉输注标记氨基酸的状态下、不同时间点上标记氨基酸的代谢终产物丰度值的差异及不同蛋白质剂量组标记氨基酸的氧化分解程度。方法20名健康青年男性分为2组,分别进食不同的蛋白质膳食,经过5天适应期后,在第6天经静脉给予13C-亮氨酸3小时,在输注结束前的半小时每隔15分钟收集受试者的呼出气样本,比较3个时间点上呼出气样品中13C的丰度值及2组受试者在输液结束时的13CO2产生率,以确定不同取样时间点上同位素丰度是否处于一个相对稳定的状态及膳食蛋白质摄入量对13CO2产生率影响。结果每组受试者在3个时间点上13C的丰度值之间差异无显著性(P>0.05),0.89g/kg蛋白质剂量组受试者的13CO2产生率高于0.80g/kg蛋白质剂量组受试者的13CO2产生率(P<0.05)。结论稳定同位素示踪技术探讨蛋白质和氨基酸的生理需要量时可以在坪台期上确定一个同一的取样时间点进而比较不同蛋白质和氨基酸剂量组的代谢动力学变化,并且摄入高剂量蛋白质组的氧化分解程度高于低剂量组。Objective To analyze the end product enrichment of the stable isotope labeled amino acid in different time points and the level of catabolism of different protein dose groups under the infusion state of the labeled amino acid in the study of amino acid metabolic kinetics, supplying the data support for the the setting of sampling time in the study of the physiological requirement of protein and amino acid. Method Twenty subjects were divided into two groups and were supplied two different doses of protein, all subjects were administered the ~ 13 C-leucine for 3 hours by the left basilic vein at 12:00 on day 6 and respired air samples were collected per 15 minutes during the last 30 minutes of infusion, analyzing the ~ 13 C enrichment difference at three time points and the ~ 13 CO_2 production rate of the two dietary protein dose groups to determine whether ~ 13 C enrichment was stable or not and how the dietary protein dose influence the ~ 13 CO_2 production rate. Result The difference of ~ 13 C enrichment is not significant at three time points for every group subjects(P>0.05), the ~ 13 CO_2 production rate of the protein dose group of 0.89g/kg/d was significantly higher than that of the protein dose group of 0.89g/kg/d(P<0.05).Conclusion It was suggested that determine one specific time point were determmed to compare the metabolic kinetics changes of the different protein and amino acid dose groups, when the physiological requirement of protein and amino acid was explored, and the catabolism level in the bigger dose group was higher than that in the smaller dose group.

关 键 词：氨基酸 稳定同位素 13CO2产生率 

分 类 号：R151.2[医药卫生—营养与食品卫生学] Q493.2[医药卫生—公共卫生与预防医学]