Regulation of intracellular pH in proximal tubules of avian long-looped mammalian-type nephrons.
Regulation of intracellular pH in proximal tubules of avian long-looped mammalian-type nephrons.
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鸟类长环哺乳动物型肾单位近端小管细胞内 pH 值的调节。
DOI：
10.1152/ajpregu.1998.274.6.r1526
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Dantzler,WH
中科院分区：
文献类型：
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作者：
Brokl,OH;Martinez,CL;Shuprisha,A;Abbott,DE;Dantzler,WH
在从鸡长环哺乳动物型肾单位分离的非灌注近端小管中，用pH敏感荧光染料2′，7′-双（2-羧基乙基）-5(6)-羧基荧光素测量的细胞内pH （pHi）在对照条件下（hepes缓冲培养基在37℃下pH为7.4）为~ 7.3，在NH4Cl脉冲下降低到~ 7.0。ph从该水平恢复到静息水平的速率是：1)从浴液中去除Na+显著降低，2)从浴液中去除Cl -显著提高，3)从浴液中去除Na+和Cl -均不变，4)在浴液中添加乙基异丙基酰胺或DIDS均显著降低，5)浴液中K+浓度高显著提高，6)浴液中添加Ba2+不变。这些数据表明，Na+偶联和Cl−偶联的碱侧酸碱通量都参与了酸化后ph恢复速率的决定。其中最有可能在调节ph中起重要作用的是Na+/H+交换器和Na+耦合Cl - /交换器。在鸟类中，长环哺乳动物型肾单位类似于短环过渡性肾单位，但与浅环爬行动物型肾单位明显不同。
In nonperfused proximal tubules isolated from chicken long-looped mammalian-type nephrons, intracellular pH (pHi), measured with the pH-sensitive fluorescent dye 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein, was ∼7.3 under control conditions (HEPES-buffered medium with pH 7.4 at 37°C) and was reduced to ∼7.0 in response to NH4Cl pulse. The rate of recovery of pHifrom this level to the resting level was1) significantly reduced by the removal of Na+from the bath,2) significantly increased by the removal of Cl−from the bath,3) unchanged by the removal of both Na+and Cl−from the bath,4) significantly reduced by the addition of either ethylisopropylamiloride or DIDS to the bath,5) significantly increased by a high bath K+concentration, and6) unchanged by the addition of Ba2+to the bath. These data suggest that both Na+-coupled and Cl−-coupled basolateral acid-base fluxes are involved in determining the rate of recovery of pHiafter acidification. The most likely ones to be important in regulating pHiare a Na+/H+exchanger and a Na+-coupled Cl−/exchanger. In birds, long-looped mammalian-type nephrons resemble short-looped transitional nephrons but differ markedly from superficial loopless reptilian-type nephrons.