Thompson K H, Turnlund J R
Western Human Nutrition Research Center, U.S. Department of Agriculture, Agricultural Research Service, Presidio of San Francisco, CA 94129-0997, USA.
J Nutr. 1996 Apr;126(4):963-72. doi: 10.1093/jn/126.4.963.
The aim of this study was to develop a compartmental model of molybdenum metabolism based on stable isotope excretion patterns. Molybdenum (Mo) is an essential trace element in humans, with an estimated safe and adequate daily dietary intake (ESADDI) of 75-250 micrograms Mo/d. Four adult men were fed low molybdenum diets, 22 micrograms Mo/d for a period of 102 d. 97Mo+ and 100Mo stable isotopes, in intravenous and oral doses, respectively, were administered at selected intervals. The resulting 6-d cumulative urinary and fecal isotope excretion data were used to model molybdenum metabolism using SAAM/CONSAM software. A kinetic model, including gastrointestinal (GI), plasma, slow-turnover tissue and fast-turn-over tissue compartments, accurately simulated the observed pattern of urinary and fecal excretion for both stable isotopes in all four subjects. Residence time for molybdenum in the GI tract was estimated at 1.7 +/- 0.4 d. Predicted residence time for plasma molybdenum was 22 +/- 4 min, whereas slow-turnover tissue (possible hepatic) retention averaged 58 +/- 16 d. The model thus permitted estimation of kinetic parameters for molybdenum metabolism in tissues not readily accessible or measurable in humans.
本研究的目的是基于稳定同位素排泄模式建立钼代谢的房室模型。钼（Mo）是人体必需的微量元素，估计每日膳食安全适宜摄入量（ESADDI）为75 - 250微克钼/天。四名成年男性食用低钼饮食，即每天22微克钼，持续102天。分别在选定的时间间隔静脉注射97Mo +和口服100Mo稳定同位素。所得的6天累积尿和粪同位素排泄数据用于使用SAAM/CONSAM软件对钼代谢进行建模。一个动力学模型，包括胃肠道（GI）、血浆、慢周转组织和快周转组织房室，准确模拟了所有四名受试者中两种稳定同位素的尿和粪排泄观察模式。钼在胃肠道的停留时间估计为1.7±0.4天。血浆钼的预测停留时间为22±4分钟，而慢周转组织（可能是肝脏）的保留平均为58±16天。因此，该模型允许估计人体中不易获取或测量的组织中钼代谢的动力学参数。
