Transepithelial acidification by cultures of rabbit proximal tubules grown on filters.
Transepithelial acidification by cultures of rabbit proximal tubules grown on filters.
复制标题
通过在过滤器上生长的兔近端小管培养物进行跨上皮酸化。
DOI：
10.1152/ajpcell.1990.259.1.c103
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Holohan,PD
中科院分区：
文献类型：
--
作者：
Ford,SM;Williams,PD;Grassl,S;Holohan,PD
近端小管跨上皮酸化是由刷状缘处的Na(+)-H+交换器和基侧Na(+)-HCO3-共转运蛋白同时作用发生的。这些系统的存在已经在培养的细胞中得到证实；然而，它们对酸等效物跨上皮运动的贡献还没有在单层中得到证实。为了检测完整细胞的跨上皮酸化，在膜过滤器上生长小管。通过降低顶室培养液的pH值(6.66+/-0.03)，同时将基侧pH值提高到7.40+/-0.02，融合培养在6h内形成跨上皮pH梯度。在此期间，保持在塑料上的细胞不会使培养液酸化。阿米洛利(10-100微米)只有在放置在顶室时才能抑制梯度的发展。4-Acetamido-4‘-isothiocyanostilbene-2，2’-disulfonic酸(SITS；10-100微米)抑制基侧Na(+)-HCO3-共转运，仅当添加到底部时才降低梯度。这些结果表明，培养的近端小管细胞可以形成跨上皮pH梯度，并在体外维持运输系统的极化分布。
Transepithelial acidification in the proximal tubule occurs by the simultaneous actions of the Na(+)-H+ exchanger in the brush border and the basolateral Na(+)-HCO3- cotransporter. The presence of these systems has been demonstrated for cultured cells; however, their contributions to the transepithelial movement of acid equivalents has not been confirmed in monolayers. To examine transepithelial acidification by intact cells, tubules were grown on membrane filters. Confluent cultures developed a transepithelial pH gradient within 6 h by decreasing the pH of medium in the apical chamber (6.66 +/- 0.03) while raising the basolateral pH to 7.40 +/- 0.02. Cells maintained on plastic did not acidify the medium during this time. Amiloride (10-100 microM) inhibited development of the gradient only when placed in the top chamber. 4-Acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS; 10-100 microM), which inhibits basolateral Na(+)-HCO3- cotransport, decreased the gradient only when added to the bottom. These results demonstrate that cultured proximal tubule cells can develop a transepithelial pH gradient and that the polarized distribution of the transport systems is maintained in vitro.