PROPERTIES OF K+-TRANSPORT IN RESEALED HUMAN-ERYTHROCYTE GHOSTS
PROPERTIES OF K+-TRANSPORT IN RESEALED HUMAN-ERYTHROCYTE GHOSTS
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DOI：
10.1152/ajpcell.1988.255.3.c346
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发表时间：
1988-09-01
影响因子：
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通讯作者：
TOSTESON, DC
中科院分区：
文献类型：
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作者：
BRUGNARA, C;VANHA, T;TOSTESON, DC
我们在这里报告我们的研究K+运输在重新密封的人红细胞血影（RG）的存在下，0.1 mM哇巴因和0.01 mM布美他尼，抑制剂的Na+-K+泵和Na+K+-Cl-共转运，分别。用凝胶过滤法获得RG。从RG的K+流出依赖于在裂解缓冲液中使用的pH，并且当pH从5.5升高至8.0时增加。在完整的红细胞，RG从细胞的最低密度部分有一个更高的K+流出比RG从细胞的致密部分。该K+通量与体积无关，并且当通量介质的pH从6.0增加到8.0时增加。K+流出（60-70%）在pH 7.40时，从RG由细胞的最低密度部分被抑制时，Cl-被硝酸盐取代，或当鬼在ATP的情况下被重新密封。这种氯离子和ATP依赖性成分在由denatrium组分的细胞制成的RG中显著减少。RG的内部Mg 2+浓度的增加，从最不密集的部分诱导显着抑制K+外流。与完整细胞相反，N-乙基马来酰亚胺（NEM）不影响RG的K+流出。因此，pH值，渗透压和NEM对RG中K+转运的影响与完整红细胞中报道的那些明显不同。
We report here our studies on K+ transport in resealed human red cell ghosts (RG) in the presence of 0.1 mM ouabain and 0.01 mM bumetanide, inhibitors of the Na+-K+ pump and Na+K+-Cl- cotransport, respectively. RG were obtained with the gel-filtration method. K+ efflux from RG was dependent on the pH used in the lysis buffer and increased when the pH was raised from 5.5 to 8.0. As in intact red cells, RG made from cells of the least dense fraction had a much higher K+ efflux than RG made from cells of the densest fraction. This K+ flux is volume independent and increases when the pH of the flux medium is increased from 6.0 to 8.0. K+ efflux (60-70%) at pH 7.40 from RG made from cells of the least dense fraction is inhibited when Cl- is substituted by nitrate or when the ghosts are resealed in the absence of ATP. This chloride- and ATP-dependent component is markedly reduced in RG made from cells of the densest fraction. An increase in the internal Mg2+ concentration in RG from the least dense fraction induced marked inhibition of K+ efflux. Contrary to intact cells, N-ethylmaleimide (NEM) did not affect K+ efflux from RG. Thus the effects of pH, osmolarity, and NEM on K+ transport in RG are markedly different from those reported in intact erythrocytes.