Dekaney C M, Harris E D, Bratton G R, Jaeger L A
Department of Veterinary Anatomy and Public Health, Texas A&M University, College Station 77843, USA.
Biol Trace Elem Res. 1997 Jul-Aug;58(1-2):13-24. doi: 10.1007/BF02910662.
This study evaluated the use of IEC-6 cells as a model for studying lead (Pb) transport by intestinal epithelial cells (IECs) and examined potential transport mechanisms for Pb uptake and extrusion. Pb accumulation in IEC-6 cells exposed to 5 and 10 microM Pb for up to 60 min was time- and dose-dependent. Reduction of incubation temperature significantly reduced the total cellular Pb content of IEC-6 cells. Simultaneous exposed of cells to zinc (Zn) and Pb resulted in decreased total cellular Pb contents compared to total cellular Pb contents of cells exposed to Pb only. IEC-6 cells treated with ouabain (1 mM) or sodium azide (1 mM) and 5 microM Pb accumulated more Pb than cells exposed to Pb only. Cells treated with p-chloromercuribenzensulfonic acid (50 microM), p-chloromercuribenzoic acid (50 microM), or iodoacetimide (50 microM) accumulated less Pb than cells treated with Pb only. We conclude that Pb uptake by IEC-6 cells depends on the extracellular Pb concentration. Our data suggest that the mechanism of Pb uptake by IECs is complex, and that Pb transport in IEC-6 cells is time- and temperature-dependent, involves sulfhydryl groups, and is decreased by the presence of Zn. Extrusion of Pb is at least partially dependent on metabolic energy.
本研究评估了使用IEC-6细胞作为研究肠道上皮细胞（IECs）铅（Pb）转运的模型，并研究了Pb摄取和排出的潜在转运机制。暴露于5和10微摩尔Pb长达60分钟的IEC-6细胞中Pb的积累呈时间和剂量依赖性。孵育温度的降低显著降低了IEC-6细胞的总细胞内Pb含量。与仅暴露于Pb的细胞相比，同时将细胞暴露于锌（Zn）和Pb导致总细胞内Pb含量降低。用哇巴因（1毫摩尔）或叠氮化钠（1毫摩尔）和5微摩尔Pb处理的IEC-6细胞比仅暴露于Pb的细胞积累了更多的Pb。用对氯汞苯磺酸（50微摩尔）、对氯汞苯甲酸（50微摩尔）或碘乙酰胺（50微摩尔）处理的细胞比仅用Pb处理的细胞积累的Pb更少。我们得出结论，IEC-6细胞对Pb的摄取取决于细胞外Pb浓度。我们的数据表明，IECs对Pb的摄取机制是复杂的，并且IEC-6细胞中Pb的转运是时间和温度依赖性的，涉及巯基，并且Zn的存在会使其降低。Pb的排出至少部分依赖于代谢能量。
