Younoszai M K, Ghishan F K
J Nutr. 1979 Apr;109(4):573-9. doi: 10.1093/jn/109.4.573.
We compared the in vivo transport of calcium (Ca) in the jejunum + ileum of 1-, 2-, 3-, 4-, and 6-week old rats. In normal rats, net absorption and the estimated bidirectional fluxes of Ca (lumen-to mucosa and mucosa-to-lumen) normalized for differences in size of the intestine (mumoles/hour per g weight) were similar in the 1-, 2-, and 3-week old rats and significantly lower in the 6-week old than in the younger rats. Growth retardation (pups raised with mothers fed a diet deficient in protein) appeared to have suppressed net absorption and the bidirectional fluxes of calcium in the 4- and 6-week old rats, but to have slightly enhanced net absorption and the bidirectional fluxes in the 1-, 2-, and 3-week old rats. These findings suggested a change in the mechanism(s) for intestinal transport of Ca during maturation. Rate of gain in body weight expressed as g/day increased with age from 1.4 g/day between 1 and 2 weeks, to 6.1 g/day between 4 and 6 weeks of age. There was no correlation between rate of net Ca absorption from the jejunum + ileum and gain in body weight expressed as g/day or as percent per day.
我们比较了1周龄、2周龄、3周龄、4周龄和6周龄大鼠空肠+回肠中钙（Ca）的体内转运情况。在正常大鼠中，根据肠道大小差异进行归一化处理后的钙净吸收以及估计的双向通量（从肠腔到黏膜和从黏膜到肠腔）（每克体重每小时微摩尔数）在1周龄、2周龄和3周龄大鼠中相似，而在6周龄大鼠中显著低于较年幼的大鼠。生长迟缓（幼崽由喂食蛋白质缺乏饮食的母鼠抚养）似乎抑制了4周龄和6周龄大鼠的钙净吸收及双向通量，但略微增强了1周龄、2周龄和3周龄大鼠的钙净吸收及双向通量。这些发现表明，在成熟过程中肠道钙转运机制发生了变化。以克/天表示的体重增加速率随着年龄增长而增加，从1至2周龄时的1.4克/天增加到4至6周龄时的6.1克/天。空肠+回肠的钙净吸收速率与以克/天或每天百分比表示的体重增加之间没有相关性。
