King J C, Shames D M, Woodhouse L R
USDA/ARS Western Human Nutrition Research Center, University of California, Davis, CA 95616, USA.
J Nutr. 2000 May;130(5S Suppl):1360S-6S. doi: 10.1093/jn/130.5.1360S.
Maintaining a constant state of cellular zinc nutrition, or homeostasis, is essential for normal function. In animals and humans, adjustments in zinc absorption and endogenous intestinal excretion are the primary means of maintaining zinc homeostasis. The adjustments in gastrointestinal zinc absorption and endogenous excretion are synergistic. Shifts in endogenous excretion appear to occur quickly with changes in intake just above or below optimal intake. The absorption of zinc responds more slowly, but it has the capacity to cope with large fluctuations in intake. With extremely low zinc intakes or with prolonged marginal intakes, secondary homeostatic adjustments may augment the gastrointestinal changes. These secondary adjustments include changes in urinary zinc excretion, a shift in plasma zinc turnover rates and, possibly, an avid retention of zinc released from selected tissues, such as bone, in other tissues to maintain function.
维持细胞锌营养的恒定状态，即锌稳态，对正常功能至关重要。在动物和人类中，锌吸收和内源性肠道排泄的调节是维持锌稳态的主要方式。胃肠道锌吸收和内源性排泄的调节是协同的。内源性排泄的变化似乎会随着摄入量略高于或低于最佳摄入量的变化而迅速发生。锌的吸收反应较慢，但它有能力应对摄入量的大幅波动。在锌摄入量极低或长期处于边缘水平时，次级稳态调节可能会增强胃肠道的变化。这些次级调节包括尿锌排泄的变化、血浆锌周转率的改变，以及可能从选定组织（如骨骼）释放的锌在其他组织中的强烈潴留以维持功能。
