Woodhead J C, Drulis J M, Rogers R R, Ziegler E E, Stumbo P J, Janghorbani M, Ting B T, Fomon S J
Department of Pediatrics, College of Medicine, University of Iowa, Iowa City 52242.
Pediatr Res. 1988 May;23(5):495-9. doi: 10.1203/00006450-198805000-00012.
Because of reluctance to use radioisotopes for studies of iron absorption in children, we have explored the feasibility of using the least abundant stable isotope of iron, 58Fe (natural abundance, 0.322 weight %) in a study of nonheme iron absorption. With a balanced cross-over design, each of 16 school-age children was fed a standardized lunch on 3 consecutive days and, 28 days later, an alternate standardized lunch on 3 consecutive days. The lunch included either a beef patty or a beef-soy patty. The mass isotope ratio, 58Fe/57Fe (MIR58/57), was measured in blood by inductively coupled plasma mass spectroscopy before and 14 days after (i.e. study day 15) consuming the three lunches. The MIR58/57 on study day 15 was used as a baseline value for lunches fed on study days 29, 30, and 31. Incorporation of 58Fe into erythrocytes was greater from the lunch with beef patty than from the lunch with beef-soy patty (geometric mean values 2.02 and 1.05% of the dose, p less than 0.03). Based on the similarity of our results with those obtained in adults with radioisotopes, we conclude that 58Fe is a satisfactory tag for studies of nonheme iron absorption from meals.
由于不愿使用放射性同位素来研究儿童的铁吸收情况，我们探讨了使用铁的最不丰富的稳定同位素58Fe（天然丰度为0.322重量%）来进行非血红素铁吸收研究的可行性。采用平衡交叉设计，16名学龄儿童每人连续3天食用一份标准化午餐，28天后，再连续3天食用另一份标准化午餐。午餐包括牛肉饼或牛肉 - 大豆饼。在食用三份午餐前及食用后14天（即研究日15），通过电感耦合等离子体质谱法测量血液中的质量同位素比值58Fe/57Fe（MIR58/57）。研究日15的MIR58/57被用作研究日29、30和31所提供午餐的基线值。与牛肉 - 大豆饼午餐相比，牛肉饼午餐中58Fe掺入红细胞的量更多（几何平均值分别为剂量的2.02%和1.05%，p小于0.03）。基于我们的结果与使用放射性同位素在成人中获得的结果的相似性，我们得出结论，58Fe是用于研究餐中非血红素铁吸收的一种令人满意的标记物。
