ESTIMATION OF THE RATE OF APPEARANCE IN THE NONSTEADY STATE WITH A 2-COMPARTMENT MODEL
ESTIMATION OF THE RATE OF APPEARANCE IN THE NONSTEADY STATE WITH A 2-COMPARTMENT MODEL
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DOI：
10.1152/ajpendo.1992.263.2.e400
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发表时间：
1992-08-01
影响因子：
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通讯作者：
MARI, A
中科院分区：
文献类型：
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作者：
MARI, A
一个简单的示踪剂为基础的方法来计算内源性物质的出现率在非稳态，从斯蒂尔方程的不一致，仍然缺乏。本文提出了一种基于二室模型的方法，通过该方法可以计算出的出现率，只有一个温和的增加复杂性斯蒂尔的方法。一个方程的出现率表示为三项之和：一个稳态项，一个长期的第一个隔间，和一个长期的第二个隔间。该公式采用三个参数，并使出现率和比活性变化之间的关系明确。还提供了用于估计每次单独运行中方法误差的方程。该算法可以用个人计算机上的电子表格来实现。采用高胰岛素正葡萄糖钳夹技术获得的模拟和实验数据作为检验。重建葡萄糖产生的时间过程的准确性明显优于使用斯蒂尔方程。内源性葡萄糖输出的显著负值是用Steele方程计算的，而不是用新方法计算的。该方法具有通用性强、简单、准确的特点，并可进行误差估计，因而适用于非稳态示踪剂分析的常规应用。
A simple tracer-based method for calculating the rate of appearance of endogenous substances in the non-steady state, free from the inconsistencies of Steele's equation, is still lacking. This paper presents a method based on a two-compartment model by which the rate of appearance can be calculated with only a modest increase in complexity over Steele's approach. An equation is developed where the rate of appearance is expressed as a sum of three terms: a steady-state term, a term for the first compartment, and a term for the second compartment. The formula employs three parameters and makes the relationship between rate of appearance and specific activity changes explicit. An equation is also provided for estimating the error of the method in each individual run. The algorithm can be implemented with a spreadsheet on a personal computer. Simulated and experimental data obtained by the hyperinsulinemic euglycemic glucose clamp technique were used as a test. The accuracy with which the time course of glucose production could be reconstructed was clearly better than that using Steele's equation. Marked negative values for endogenous glucose output were calculated with Steele's equation but not with the new method. The characteristics of generality, simplicity, and accuracy and the availability of an error estimate make this new method suitable for routine application to non-steady-state tracer analysis.