Naber T H, van den Hamer C J, van den Broek W J, Roelofs H
Department of Medicine, University Hospital Nijmegen, The Netherlands.
Biol Trace Elem Res. 1994 Oct-Nov;46(1-2):29-50. doi: 10.1007/BF02790066.
Determination of zinc concentrations in white blood cells has been used to establish zinc deficiency. During pathological conditions changes in zinc concentrations in these blood cells were observed. However, these investigations were hampered by the low amount of zinc in this form per mL blood. Earlier we demonstrated that, in the case of zinc deficiency, the uptake of zinc was increased, using the in vitro exchange of zinc by the various blood cells with extracellular zinc labeled with 65Zn in fairly physiologic conditions. In case of inflammation, no increase in zinc uptake by erythrocytes was seen, indicating that this method probably can be used to differentiate real from apparent zinc deficiency. Only during the first days of the inflammatory process, probably representing the redistribution phase during which zinc moves from the serum to the liver, a small increase in in vitro zinc uptake was seen in mononuclear cells (MNC) and polymorphonuclear cells (PMNC). Earlier papers raised some questions; e.g., is the uptake part of an exchange process and can the efflux of zinc by the cells be measured by the same method; what is the influence of time on the process of zinc uptake; what is the magnitude of the uptake of zinc by the cells compared to the zinc concentration in the cells; and, what is the influence of temperature on the uptake of zinc? In the present study, the influence of incubation time and temperature on the uptake of zinc by human and rat blood cells and on the release of zinc by rat blood cells was studied. At least three phases of uptake of zinc in the various cells were found by varying the incubation time--a fast phase during the first half hour, probably caused by an aspecific binding of zinc on or in the cell membrane; a second fast uptake between 60-330 min, probably caused by an influx of zinc in the cell as part of the exchange process of zinc; and a slow third phase after 5.5 h, in which probably the in- and efflux of the rapidly exchangeable intracellular pool is more or less equilibrated. For mononuclear cells, polymorphonuclear cells, and erythrocytes of rats, the rapidly exchangeable intracellular pool is 40%, 53%, and 10%, respectively, of the total zinc content of the cells. This study is also performed in human cells; in human cells the exchangeable pool of mononuclear cells and erythrocytes is 17 and 3.5% of the total zinc content of the cells, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)
测定白细胞中的锌浓度已被用于确定锌缺乏情况。在病理状态下，观察到这些血细胞中锌浓度的变化。然而，每毫升血液中这种形式的锌含量较低，阻碍了这些研究。早些时候我们证明，在锌缺乏的情况下，在相当生理的条件下，通过用65Zn标记的细胞外锌与各种血细胞进行锌的体外交换，锌的摄取会增加。在炎症情况下，未观察到红细胞对锌的摄取增加，这表明该方法可能可用于区分真正的锌缺乏和表观锌缺乏。仅在炎症过程的最初几天，可能代表锌从血清转移到肝脏的重新分布阶段，单核细胞（MNC）和多形核细胞（PMNC）的体外锌摄取有小幅增加。早期的论文提出了一些问题；例如，摄取是交换过程的一部分吗，细胞锌的外流能用同一方法测量吗；时间对锌摄取过程有什么影响；与细胞内锌浓度相比，细胞摄取锌的量有多大；以及温度对锌摄取有什么影响？在本研究中，研究了孵育时间和温度对人和大鼠血细胞摄取锌以及大鼠血细胞释放锌的影响。通过改变孵育时间，在各种细胞中发现了至少三个锌摄取阶段——前半小时的快速阶段，可能是由于锌在细胞膜上或膜内的非特异性结合；60 - 330分钟之间的第二个快速摄取阶段，可能是由于锌作为锌交换过程的一部分流入细胞；以及5.5小时后的缓慢第三阶段，其中快速可交换细胞内池的流入和流出可能大致平衡。对于大鼠的单核细胞、多形核细胞和红细胞，快速可交换细胞内池分别占细胞总锌含量的40%、53%和10%。本研究也在人细胞中进行；在人细胞中，单核细胞和红细胞的可交换池分别占细胞总锌含量的17%和3.5%。（摘要截取自400字）
