pH regulatory mechanisms in rat pancreatic ductal cells.
pH regulatory mechanisms in rat pancreatic ductal cells.
复制标题
大鼠胰腺导管细胞的 pH 调节机制。
DOI：
10.1152/ajpgi.1988.254.6.g925
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Williams,JA
中科院分区：
文献类型：
--
作者：
Stuenkel,EL;Machen,TE;Williams,JA
通过使用 pH 敏感的荧光细胞质捕获染料 2',7'-双(羧乙基)-5(6)-羧基荧光素 (BCECF)，研究了大鼠胰管细胞调节细胞内 pH (pHi) 的机制。根据 BCECF 荧光比计算，细胞在碳酸氢盐缓冲培养基中的平均 pHi 为 7.18 +/- 0.14。细胞外 Na (Nao) 的去除引起细胞内酸化，这种酸化可通过 Na 替代而迅速逆转，并且独立于 Clo 发生。阿米洛利 (10(-3) M) 可逆地阻断无钠诱导酸化后的钠依赖性恢复。这些结果证明胰管细胞中存在 Na+-H+ 交换机制。用葡萄糖酸取代 Clo 会导致细胞内碱化，而用 Cl 取代可逆转这种碱化。二磺酸二苯乙烯衍生物、4,4'-二异硫氰基二苯乙烯-2,2'-二磺酸 (DIDS) 和二氢-DIDS (2 X 10(-4) M) 的应用，导致了从葡萄糖酸钠的 Cl 依赖性回收和从 NaCl 到葡萄糖酸钠的碱化开始的阻断。 pHi 的氯化物依赖性改变独立于 Nao 发生。这些结果表明存在与 Cl--HCO3- 交换一致的阴离子交换机制。因此胰管细胞含有Na+-H+和Cl--HCO3-交换剂。
The mechanisms underlying regulation of intracellular pH (pHi) by rat pancreatic duct cells were studied by use of the pH-sensitive, fluorescent, cytoplasmically trapped dye 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF). Cells exhibited a mean pHi of 7.18 +/- 0.14 in bicarbonate-buffered medium, as calculated from the BCECF fluorescence ratio. Removal of extracellular Na (Nao) caused an intracellular acidification that was rapidly reversed by Na replacement and occurred independently of Clo. Amiloride (10(-3) M) reversibly blocked Na-dependent recovery after Na-free-induced acidification. These results demonstrate the presence of a Na+-H+ exchange mechanism in pancreatic duct cells. Replacement of Clo with gluconate caused an intracellular alkalinization that was reversed by replacement of Cl. Application of the disulfonic stilbene derivatives, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) and dihydro-DIDS (2 X 10(-4) M), resulted in block of both Cl-dependent recovery from Na-gluconate and the onset of alkalinization of transition from NaCl to Na-gluconate. Chloride-dependent alteration of pHi occurred independently of Nao. These results demonstrate the presence of an anion exchange mechanism consistent with Cl--HCO3- exchange. Thus pancreatic duct cells contain both Na+-H+ and Cl--HCO3- exchangers.