MEASUREMENT OF SIZE AND TURNOVER RATE OF BODY GLUCOSE POOL BY THE ISOTOPE DILUTION METHOD
MEASUREMENT OF SIZE AND TURNOVER RATE OF BODY GLUCOSE POOL BY THE ISOTOPE DILUTION METHOD
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DOI：
10.1152/ajplegacy.1956.187.1.15
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发表时间：
1956-01-01
影响因子：
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通讯作者：
ALTSZULER, N
中科院分区：
文献类型：
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作者：
STEELE, R;WALL, JS;ALTSZULER, N
将C14均匀标记的葡萄糖以微量静脉内给予处于吸收后状态的未麻醉犬，作为初始剂量，然后连续输注。每隔一段时间测定血浆葡萄糖的C14含量。当预充剂量与输注速率的比率合适时，在60-180分钟输注期间，血浆葡萄糖比活度保持相对恒定，而在前60分钟期间，其以指示存在与血浆葡萄糖隔室交换葡萄糖的两个隔室的方式降低。对于这种典型的实验，计算这些隔室中葡萄糖的量以及这些葡萄糖体与血浆葡萄糖混合的速率。然后可以确定身体葡萄糖池大小和流入-流出（即，转换）速率，这是在预充剂量与输注速率的各种比率下进行测量时得到的。当通常的简化假设是在整个身体葡萄糖池中发生瞬时混合时，就会产生这些误差。研究发现，初始剂量与输注速率的比值范围很广，误差足够小（小于[±] 5%），可以忽略不计;没有必要对每只犬进行初步实验以确定理想的比值。用7只正常狗进行10次实验，获得了体葡萄糖池大小和葡萄糖流入-流出速率的平均值，并与其他人报道的值进行了比较。讨论了同位素稀释法测定这些参数的生理意义。
Glucose uniformly labeled with C14 was administered intravenously in minute amounts to unanesthetized dogs in the postabsorptive state as an initial dose followed by a conti-nous infusion. The C14 content of the plasma glucose was determined at intervals. When the ratio of priming dose to infusion rate was suitable, the plasma glucose specific activity remained relatively constant during the 60-180 minute period of the infusion, whereas during the first 60 minutes it decreased in a manner indicating the presence of two compartments exchanging glucose with the plasma glucose compartment. For a typical experiment of this kind, the amounts of glucose in these compartments and the rates at which these bodies of glucose underwent mixing with the plasma glucose were calculated. It was then possible to determine the magnitude of the errors in body glucose pool size and inflow-outflow (i.e., turnover) rate which are made when measurements are carried out at various ratios of priming dose to infusion rate. These errors are incurred when the usual simplifying assumption is made that instantaneous mixing occurs throughout the body glucose pool. It was found that there is an extensive range of ratios of initial dose to infusion rate over which the errors are small enough (less than [plus or minus] 5%) to be ignored; it is not necessary to carry out a preliminary experiment on each dog to establish a desirable ratio. Average values of body glucose pool size and glucose inflow-outflow rate obtained in 10 experiments with seven normal dogs are compared with values which have been reported by others. The physiological significance of these parameters measured by isotope dilution is discussed.