Oestreicher P, Cousins R J
Food Science and Human Nutrition Department, University of Florida, Gainesville 32611.
J Nutr. 1989 Apr;119(4):639-46. doi: 10.1093/jn/119.4.639.
Zinc uptake (transport and binding) by basolateral membrane vesicles was investigated using membranes derived from small intestines of rats fed zinc-adequate and zinc-deficient diets. Uptake was separated into saturable and nonsaturable (diffusion) components. Kinetic analysis of initial rates of the saturable component of uptake (at 1 min) indicates half maximal uptake (Km) by vesicles from zinc-adequate rats was observed at a medium Zn2+ concentration of 24 microM. The maximum Zn2+ uptake rate (Jmax) of the saturable component was 17 nmol/(mg protein.min). Dietary zinc intake did not affect these parameters. Zn2+ transport by the basolateral membrane may involve an ATP-driven mechanism.
使用取自喂食锌充足和锌缺乏饮食的大鼠小肠的膜，研究了基底外侧膜囊泡对锌的摄取（运输和结合）。摄取被分为可饱和和不可饱和（扩散）成分。对摄取的可饱和成分的初始速率（1分钟时）进行动力学分析表明，锌充足大鼠的囊泡在24 microM的中等锌离子浓度下观察到半数最大摄取量（Km）。可饱和成分的最大锌离子摄取速率（Jmax）为17 nmol/（mg蛋白质·分钟）。饮食中的锌摄入量不影响这些参数。基底外侧膜对锌离子的运输可能涉及一种ATP驱动的机制。
