Taylor C M, Bacon J R, Aggett P J, Bremner I
Rowett Research Institute, Bucksburn, Aberdeen, UK.
Eur J Clin Nutr. 1991 Apr;45(4):187-94.
The absorption and intestinal losses of endogenous Cu in response to a low Zn diet were studied in five young male subjects using stable 65Cu as an oral tracer. The subjects received a semi-purified formula diet providing 85 mumol (5.6 mg) Zn/d during 15-day baseline and repletion phases and 12 mumol (0.8 mg) Zn/d during an intervening period of 25 days. Thirty-eight mumol (2.4 mg) Cu/d was provided throughout the study. In four of the subjects, the mean +/- SEM luminal disappearance of 65Cu was 37 +/- 4 per cent during the baseline phase and was unaffected by Zn deprivation (32 +/- 7 per cent) or repletion (30 +/- 7 per cent) as were intestinal losses of endogenous Cu [7 +/- 4, 8 +/- 3, 8 +/- 3 mumol/d (0.4 +/- 0.1, 0.5 +/- 0.1, 0.5 +/- 0.1 mg/d) during baseline, Zn deprivation and Zn repletion phases, respectively]. In a fifth subject, who had some evidence of a resolving alcohol-induced hepatitis, the luminal disappearance of 65Cu was 31, 44 and 42 per cent and the intestinal losses of endogenous Cu 11, 2 and 6 mumol/d (0.7, 0.1 and 0.4 mg/d) during the baseline, Zn deprivation and Zn repletion phases respectively. Plasma Cu concentrations, however, fell throughout the study in all the subjects, despite consistently positive Cu balances. There may be subtle effects of a low dietary intake of Zn on Cu metabolism which were not revealed by the methods used in this study.
在五名年轻男性受试者中，使用稳定的65Cu作为口服示踪剂，研究了低锌饮食对内源性铜吸收和肠道损失的影响。受试者在15天的基线期和补充期接受半纯化配方饮食，提供85微摩尔（5.6毫克）锌/天，在25天的中间期接受12微摩尔（0.8毫克）锌/天。在整个研究过程中，每天提供38微摩尔（2.4毫克）铜。在四名受试者中，65Cu的平均±标准误管腔消失率在基线期为37±4%，不受锌缺乏（32±7%）或补充（30±7%）的影响，内源性铜的肠道损失也不受影响[基线期、锌缺乏期和锌补充期分别为7±4、8±3、8±3微摩尔/天（0.4±0.1、0.5±0.1、0.5±0.1毫克/天）]。在第五名受试者中，有一些酒精性肝炎正在好转的迹象，65Cu的管腔消失率在基线期、锌缺乏期和锌补充期分别为31%、44%和42%，内源性铜的肠道损失分别为11、2和6微摩尔/天（0.7、0.1和0.4毫克/天）。然而，尽管铜平衡一直为正，但在整个研究过程中，所有受试者的血浆铜浓度均下降。低锌饮食摄入可能对铜代谢有细微影响，而本研究中使用的方法未揭示这些影响。
