Hagos Y, Krick W, Burckhardt G
Zentrum Physiologie und Pathophysiologie, Humboldtallee 23, D-37073 Göttingen, Germany.
Pflugers Arch. 1999 Apr;437(5):724-30. doi: 10.1007/s004240050838.
Vesicles enriched in a marker enzyme for apical membranes were isolated from HT29 cells. These vesicles contain an anion conductance with the selectivity gluconate approximately sulphate<F-<Cl-<Br-<NO3-<I-<SCN-. K+ diffusion potential-driven 36Cl- uptake was inhibited by 5-nitro-2-(3-phenylpropylamino)benzoate (NPPB)>4, 4'-diisothiocyanatostilbene-2,2'-disulphonate (DIDS)>glibenclamide. The Cl- conductance was insensitive to Ca2+ and to extravesicular cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP) and inosine 5'-triphosphate (ITP). Using the reverse transcription polymerase chain reaction (RT-PCR) technique and sequencing of the amplified products we detected messenger ribonucleic acid (mRNA) for the cystic fibrosis transmembrane conductance regulator (CFTR), the putative Cl- channel or Cl- channel regulator pICln, and the Cl- channels ClC-2, ClC-3, ClC-5 and ClC-6 in HT29 cells. The properties of the vesicles' Cl- conductance resemble those of the intermediate conductance outwardly rectifying Cl- channel and tentatively exclude contributions of CFTR, pICln and ClC-2. Whether ClC-3, ClC-5, ClC-6 are involved in Cl- conductance remains to be determined.
从HT29细胞中分离出富含顶端膜标记酶的囊泡。这些囊泡含有一种阴离子电导，其选择性为葡萄糖酸盐＞硫酸盐＞氟离子＞氯离子＞溴离子＞硝酸根离子＞碘离子＞硫氰酸根离子。钾离子扩散电位驱动的36Cl-摄取受到5-硝基-2-(3-苯丙基氨基)苯甲酸酯(NPPB)＞4,4'-二异硫氰酸根合芪-2,2'-二磺酸盐(DIDS)＞格列本脲的抑制。氯离子电导对钙离子以及囊泡外的环磷酸腺苷(cAMP)、环磷酸鸟苷(cGMP)和三磷酸肌苷(ITP)不敏感。使用逆转录聚合酶链反应(RT-PCR)技术并对扩增产物进行测序，我们在HT29细胞中检测到了囊性纤维化跨膜电导调节因子(CFTR)、假定的氯离子通道或氯离子通道调节因子pICln以及氯离子通道ClC-2、ClC-3、ClC-5和ClC-6的信使核糖核酸(mRNA)。囊泡氯离子电导的特性类似于中等电导外向整流氯离子通道，初步排除了CFTR、pICln和ClC-2的作用。ClC-3、ClC-5、ClC-6是否参与氯离子电导仍有待确定。
