Multicompartment analysis of 14C-labelled coproporphyrin and uroporphyrin kinetics in human beings.
Multicompartment analysis of 14C-labelled coproporphyrin and uroporphyrin kinetics in human beings.
复制标题
人类 14C 标记粪卟啉和尿卟啉动力学的多室分析。
DOI：
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发表时间：
1976
期刊：
影响因子：
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通讯作者：
M. Kekki
中科院分区：
文献类型：
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作者：
P. Koskelo;M. Kekki
将~(14)C标记的共卟啉I、Ⅲ和尿卟啉I静脉注射到健康人体内。每种卟啉都进行了两次实验。血液、尿液和粪便的计数随着时间的变化而进行。用带延迟池的四室模型在模拟计算机上模拟了共比例卟啉的数据。这些隔室的生理对应物被认为是肝脏、血液和肠道。从尿卟啉的血液放射性消失曲线可以计算出三个指数分量。采用最小二乘法求解血、尿放射性曲线。建立了一个三房室模型来解释尿卟啉I的动力学行为，而共卟啉I和Ⅲ的动力学行为基本上是相似的，而尿卟啉I的动力学行为则完全不同于共卟啉。肝脏快速摄取、优先排泄粪便和显著的肠-肝循环是共比例卟啉动力学的特征。超过70%的尿卟啉I示踪活性被发现累积到一个相当大的池中(体积是血浆体积的16-28倍)，从那里返回到血浆的流动相当缓慢。几乎所有的尿卟啉都是通过尿液排出的。
14C-labelled coproporphyrin I and III and uroporphyrin I were injected intravenously into healthy human subjects. Two experiments were performed with each porphyrin. Counting of blood, urine and faeces was made as a function of time. The coproporphyrin data were simulated by means of an analogy computer by using a four-compartment model with a delay pool. The physiological counterparts to the compartments were considered to be liver, blood and gut. From the blood radioactivity disappearance curve of uroporphyrin three exponential components could be worked out. The least square method was used for the solution of the plasma and urine radioactivity curves. A three-compartment model was constructed to illustrate the kinetics of uroporphyrin I. Coproporphyrin I and III behaved essentially similarly, whilst the kinetic behaviour of uroporphyrin I was completely different from that of coproporphyrins. A rapid hepatic uptake, preferential faecal excretion and a significant enterohepatic circulation were features of coproporphyrin kinetics. Over 70 per cent of the tracer activity of uroporphyrin I was found to accumulate to a rather large pool (volume 16--28 times the plasma volume) from where the back flow to plasma was rather slow. Practically all the uroporphyrin was excreted via urine.