Miller L V, Hambidge K M, Naake V L, Hong Z, Westcott J L, Fennessey P V
University of Colorado Health Sciences Center, Center for Human Nutrition, Denver 80262.
J Nutr. 1994 Feb;124(2):268-76. doi: 10.1093/jn/124.2.268.
A relatively simple technique was used to estimate the size of the combined pools of zinc with which plasma zinc exchanges within 2 d (EZP). EZP size was determined from the amount of isotope introduced into the plasma and the coefficient of the simple exponential decay function fitting enrichment data between d 3 and 9 after isotope administration. Using data from 11 healthy adults, comparisons were made of EZP size estimations using oral and intravenous isotopes (r = 0.93 using urine) and urine and plasma enrichment (r = 0.85 for intravenous). EZP size estimations from urine and plasma enrichment following intravenous isotope administration were 2.35 +/- 0.84 and 2.83 +/- 0.86 mmol, respectively (mean +/- SD, P < 0.01). EZP size correlated with habitual dietary zinc intake (partial r = 0.74, P < 0.02). Cumulative declines in EZP size in two healthy adults after 3 wk of consuming a moderately zinc-restricted diet followed by 1 wk of severe zinc restriction were 26 and 32%. These results indicated that EZP size is dependent on dietary intake. We conclude that this technique is adequate to demonstrate EZP differences that are of nutritional and physiological interest. EZP size estimates can be obtained using orally or intravenously administered isotope and using plasma or urine enrichment data.
采用一种相对简单的技术来估算在2天内与血浆锌进行交换的锌的联合池大小（EZP）。EZP大小是根据引入血浆的同位素量以及在给予同位素后第3天至第9天对富集数据进行拟合的简单指数衰减函数系数来确定的。利用11名健康成年人的数据，对使用口服和静脉同位素的EZP大小估算值进行了比较（使用尿液时r = 0.93），以及对尿液和血浆富集情况进行了比较（静脉注射时r = 0.85）。静脉注射同位素后，根据尿液和血浆富集情况估算的EZP大小分别为2.35±0.84和2.83±0.86 mmol（平均值±标准差，P < 0.01）。EZP大小与习惯性膳食锌摄入量相关（偏相关系数r = 0.74，P < 0.02）。两名健康成年人在摄入适度锌限制饮食3周后再进行1周严格锌限制，其EZP大小的累积下降分别为26%和32%。这些结果表明EZP大小取决于膳食摄入量。我们得出结论，该技术足以证明具有营养和生理意义的EZP差异。可以使用口服或静脉注射的同位素以及血浆或尿液富集数据来获得EZP大小的估算值。
