Stuart M A, Johnson P E
J Nutr. 1986 Jun;116(6):1028-36. doi: 10.1093/jn/116.6.1028.
Copper (Cu) balance and absorption were studied to determine the extent to which absorption is dependent on dietary Cu. Over 12 consecutive 5-d metabolic periods, Cu balance was determined for four groups of young growing rats (n = 8) fed modified AIN-76 diets having different levels of added Cu (2.5, 5.0, 10 or 20 micrograms/g). Among groups, mean body weights did not differ over time (P greater than 0.05). There were no significant differences among groups for liver, heart or plasma Cu. Rats in all groups were in positive Cu balance throughout the study. After consuming the experimental diets for 10 d, rats eating 10 or 20 micrograms Cu/g diet showed a more positive Cu balance than did rats in the other groups. This trend continued until d 60. For rats eating 20 micrograms Cu/g diet, balance varied significantly over time. Three test meals labeled with stable 65Cu were fed at d 10, 40 and 50, respectively. Apparent Cu absorption, as determined by fecal monitoring of 65Cu, did not change appreciably over time for rats eating 2.5 or 5.0 micrograms Cu/g diet. A test meal labeled with radioactive 67Cu was fed at d 40. For rats eating 2.5 micrograms Cu/g diet, apparent absorption was higher (31%) than that for all other groups (5.0, 23%; 10, 19%; 20, 16%; P less than 0.05). Absorption values determined by whole-body retention of 67Cu were similar to those determined by fecal monitoring of 65Cu.
研究了铜（Cu）平衡与吸收情况，以确定吸收对膳食铜的依赖程度。在连续12个为期5天的代谢周期内，对四组幼年生长大鼠（n = 8）进行铜平衡测定，这些大鼠喂食添加了不同水平铜（2.5、5.0、10或20微克/克）的改良AIN - 76日粮。各组之间，平均体重随时间无差异（P大于0.05）。各组在肝脏、心脏或血浆铜方面无显著差异。在整个研究过程中，所有组的大鼠铜平衡均为正值。食用实验日粮10天后，摄入10或20微克铜/克日粮的大鼠比其他组的大鼠铜平衡更积极。这一趋势持续到第60天。对于摄入20微克铜/克日粮的大鼠，平衡随时间变化显著。分别在第10天、40天和50天喂食了三次标记有稳定65Cu的测试餐。通过对65Cu进行粪便监测确定的表观铜吸收，对于摄入2.5或5.0微克铜/克日粮的大鼠，随时间没有明显变化。在第40天喂食了一次标记有放射性67Cu的测试餐。对于摄入2.5微克铜/克日粮的大鼠，表观吸收率更高（31%），高于所有其他组（5.0微克/克，23%；10微克/克，19%；20微克/克，16%；P小于0.05）。通过67Cu全身滞留测定的吸收值与通过65Cu粪便监测测定的吸收值相似。
