Seal C J
Department of Agricultural Biochemistry and Nutrition, University of Newcastle upon Tyne, UK.
Ann Nutr Metab. 1988;32(4):186-91. doi: 10.1159/000177440.
Male rats were fed isonitrogenous, isocaloric diets containing different amounts of dietary zinc and picolinic acid (PA) (25, 60, 120 ppm Zn, 0, 20, 40, 60 mmol PA/kg diet) and balance collections of urine and faeces made over a 4-day period. Rats fed 25 ppm Zn were in negative Zn and Cu balance during the experiment. Faecal Zn, but not urinary Zn excretion was elevated with increasing dietary Zn supply. Urinary Zn, Cu and Mg excretion increased with increasing intakes of dietary PA, regardless of Zn intake. Tissue Zn levels were unaffected by dietary Zn or PA. It is concluded that dietary PA forms soluble complexes with metal ions which are rapidly absorbed but are then re-excreted in urine and may not be available for metabolism or incorporation into tissues.
给雄性大鼠喂食含不同量膳食锌和吡啶甲酸（PA）（锌含量为25、60、120 ppm，PA含量为0、20、40、60 mmol/kg膳食）的等氮、等热量饮食，并在4天内收集尿液和粪便进行平衡分析。实验期间，喂食25 ppm锌的大鼠锌和铜处于负平衡状态。随着膳食锌供应量的增加，粪便锌排泄量升高，但尿锌排泄量未升高。无论锌摄入量如何，尿锌、铜和镁的排泄量均随着膳食PA摄入量的增加而增加。组织锌水平不受膳食锌或PA的影响。得出的结论是，膳食PA与金属离子形成可溶性复合物，这些复合物迅速被吸收，但随后又通过尿液重新排出，可能无法用于新陈代谢或整合到组织中。
