Schuette S A, Janghorbani M, Young V R, Weaver C M
Clinical Nutrition Research Unit, University of Chicago, IL.
J Am Coll Nutr. 1993 Jun;12(3):307-15. doi: 10.1080/07315724.1993.10718315.
Two studies were conducted to determine if dysprosium (Dy) could be used as a quantitative fecal marker for studies of zinc-70 (70Zn), copper-65 (65Cu) and magnesium-26 (26Mg) absorption in humans. In the first experiment, Dy excretion was shown to be complete (104 +/- 9%; mean +/- SD, n = 6) and the kinetics of fecal Dy excretion closely paralleled that of 70Zn but not 65Cu. Because of the similarity in 70Zn and Dy excretion kinetics, a method for estimating 70Zn absorption was developed which used 70Zn and Dy data from only the first two stools passed after isotope administration. Average estimates of 70Zn absorption based on the two-stool (partial pool) vs total pool (5-day composite) method were not different (28.0 +/- 5.2 vs 24.4 +/- 4.1%, respectively; means +/- SEM; p > 0.10). In the second study, the same questions was addressed relative to 26Mg absorption. 26Mg and Dy also exhibited nearly identical excretion patterns. Average estimates of 26Mg absorption based on the partial pool vs total pool method were comparable yielding mean values of 22.7 +/- 3.4 vs 23.2 +/- 2.5% and 26.1 +/- 1.8 vs 24.3 +/- 1.8%, respectively, from magnesium-26 oxide (26MgO) and 26Mg glycinate. Advantages and limitations of the partial pool method for estimating mineral absorption are discussed.
开展了两项研究，以确定镝（Dy）是否可作为一种定量粪便标记物，用于人体锌-70（70Zn）、铜-65（65Cu）和镁-26（26Mg）吸收的研究。在第一个实验中，镝的排泄被证明是完全的（104±9%；平均值±标准差，n = 6），粪便中镝排泄的动力学与70Zn密切平行，但与65Cu不平行。由于70Zn和镝排泄动力学相似，开发了一种估算70Zn吸收的方法，该方法仅使用同位素给药后排出的前两份粪便中的70Zn和镝数据。基于两份粪便（部分池）与总池（5天综合）方法的70Zn吸收平均估算值没有差异（分别为28.0±5.2%和24.4±4.1%；平均值±标准误；p>0.10）。在第二项研究中，针对26Mg吸收提出了同样的问题。26Mg和镝也表现出几乎相同的排泄模式。基于部分池与总池方法的26Mg吸收平均估算值具有可比性，分别从氧化镁-26（26MgO）和甘氨酸镁-26得到的平均值为22.7±3.4%和23.2±2.5%，以及26.1±1.8%和24.3±1.8%。讨论了估算矿物质吸收的部分池方法的优缺点。
