A compartmental model of zinc metabolism in healthy women using oral and intravenous stable isotope tracers
A compartmental model of zinc metabolism in healthy women using oral and intravenous stable isotope tracers
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DOI：
10.1093/ajcn/65.6.1810
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发表时间：
1997-06-01
影响因子：
7.1
通讯作者：
King, JC
中科院分区：
文献类型：
--
作者：
Lowe, NM;Shames, DM;King, JC
A mathematical model of zinc metabolism in six healthy women (average age: 30 +/- 11 y) was developed by using stable isotopes of zinc. After equilibration on a constant diet containing 7.0 mg Zn/d, an oral tracer highly enriched in Zn-67 and an intravenous tracer highly enriched in Zn-70 were administered simultaneously. Multiple plasma and 24-h urine samples were collected for the next 7 d with complete fecal collections for 11 d. Tracer-tracee ratios in plasma, urine, and feces were calculated from isotope ratios of Zn-67 to Zn-66 and Zn-70 to Zn-66 measured by using inductively coupled plasma-mass spectrometry. An a priori identifiable model composed of seven compartments was developed to describe the kinetics of both tracers as well as that of naturally occurring zinc. The parameters of the model were fitted to the data by using the SAAM-CONSAM modeling software and were estimated with good precision. Several important, not directly measurable zinc variables were estimated ((x) over bar +/- SEM) from the model including the fractional absorption from the gastrointestinal tract (0.279 +/- 0.043), the rates of endogenous secretion (2.79 +/- 0.49 mg/d) and excretion (2.01 +/- 0.35 mg/d), the fractional turnover rate of the plasma pool (131 +/- 20/d), and the sizes (7.2 +/- 1.2 and 77.1 +/- 6.4 mg) and fractional turnover rates (22.3 +/- 7.1 and 1.49 +/- 0.18/d) of the fast and slow tissue pools equilibrating with the plasma, respectively.
