Aldosterone activates Na+/H+ exchange and raises cytoplasmic pH in target cells of the amphibian kidney.
Aldosterone activates Na+/H+ exchange and raises cytoplasmic pH in target cells of the amphibian kidney.
复制标题
醛固酮激活两栖动物肾脏靶细胞中的 Na /H 交换并提高细胞质 pH 值。
DOI：
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发表时间：
1987
影响因子：
11.1
通讯作者：
W. Wang
中科院分区：
文献类型：
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作者：
H. Oberleithner;M. Weigt;H. Westphale;W. Wang
这一假说得到了验证，即矿化皮质激素醛固酮是否能刺激从蛙肾远端肾单位的单个靶细胞融合而来的“巨细胞”中的Na+/H+交换。用微电极连续记录融合细胞的稳态pH(Phi)和从酸负荷中恢复的phi。加入激素后20min，pHi开始升高，约60min后达到一个新的稳定状态(Delta Phi=0.28+/-0.01)。激素处理后，phi对细胞内酸负荷的反应恢复得更快。利尿剂阿米洛利阻碍了phi的恢复。在完整小管上的实验表明，醛固酮能诱导H+和K+的分泌。因此，Na+/H+交换介导的细胞内碱中毒可能是激活腔细胞膜pH敏感K+通道的信号。
The hypothesis was tested if the mineralocorticoid hormone aldosterone stimulates Na+/H+ exchange in "giant cells" fused from individual target cells of the distal nephron of the frog kidney. By means of microelectrodes, steady-state intracellular pH (pHi) and pHi recovery from an acid load were recorded continuously while the fused cells were exposed to aldosterone. Twenty minutes after addition of the hormone, pHi started to rise and reached a new steady state after about 60 min (delta pHi = 0.28 +/- 0.01). After hormone treatment, pHi recovered significantly faster in response to an intracellular acid load. The diuretic drug amiloride blocked pHi recovery. Experiments in intact tubules showed that aldosterone induces H+ and K+ secretion. Thus, intracellular alkalosis, mediated by Na+/H+ exchange, could serve as a signal that activates pH-sensitive K+ channels of the luminal cell membrane.