Effects of NH4Cl and dimethylamine on Cl- fluxes in resting and stimulated rat submandibular acinar cells.
Effects of NH4Cl and dimethylamine on Cl- fluxes in resting and stimulated rat submandibular acinar cells.
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NH4Cl 和二甲胺对静息和刺激大鼠颌下腺泡细胞中 Cl-通量的影响。
DOI：
10.1152/ajpgi.1992.263.4.g558
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Martinez,JR
中科院分区：
文献类型：
--
作者：
Seagrave,JC;Barker,S;Curry,M;Martinez,JR
唾液腺泡细胞中K+和Cl-的跨膜运动在唾液的形成中起重要作用，并可能受到细胞内pH(Phi)变化的影响。暴露在NH4Cl中会短暂地增加phi，但NH4+的影响可能不依赖于Phi。为了研究在这些条件下氯离子转运的变化，我们将大鼠颌下腺泡暴露于NH4Cl中，并用36Cl-研究了氯离子跨膜转运。NH4Cl使这些细胞内的氯离子含量增加。这种增加的初始阶段部分依赖于HCO(3-)，并被1 mM的4，4‘-二异硫氰基二苯乙烯-2，2’-二磺酸(DIDS)所抑制，而持续阶段则被0.1 mM的布美他尼所抑制。NH4Cl还能抑制乙酰胆碱诱导的示踪剂预负荷细胞的氯离子外流。PH的变化在时间或程度上并不总是与氯-转运的变化相关。我们得出的结论是：1)暴露于NH4Cl主要通过对布美他尼敏感的转运系统增加对氯的摄取，而该转运系统在实验过程中并未达到稳定状态；2)暴露于NH4Cl也通过DIDS敏感的机制刺激对氯的摄取；3)只有后者是Phi敏感的。
Transmembrane movements of K+ and Cl- in salivary acinar cells are important in the formation of saliva, and may be affected by changes in intracellular pH (pHi). Exposure to NH4Cl increases pHi transiently, but NH4+ may have effects independent of pHi. To investigate how Cl- transport may be altered under these conditions, rat submandibular acini were exposed to NH4Cl, and transmembrane Cl- transport was studied with 36Cl-. NH4Cl increased intracellular Cl- in these cells. The initial phase of this increase was partially HCO(3-)-dependent and was inhibited by 1 mM 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), while the sustained phase was inhibited by 0.1 mM bumetanide. NH4Cl also inhibited acetylcholine-induced Cl- efflux from tracer preloaded cells. Changes in pH did not always correlate in time or extent with those of Cl- transport. We conclude that 1) exposure to NH4Cl increases Cl-uptake primarily by a bumetanide-sensitive transport system that did not reach steady state during the experiment, 2) exposure to NH4Cl also stimulates Cl- uptake by a DIDS-sensitive mechanism, and 3) only the latter is pHi sensitive.