EVIDENCE FOR NEUTRAL TRANS-CELLULAR NACL TRANSPORT AND NEUTRAL BASOLATERAL CHLORIDE EXIT IN THE RABBIT PROXIMAL CONVOLUTED TUBULE
EVIDENCE FOR NEUTRAL TRANS-CELLULAR NACL TRANSPORT AND NEUTRAL BASOLATERAL CHLORIDE EXIT IN THE RABBIT PROXIMAL CONVOLUTED TUBULE
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DOI：
10.1172/jci111403
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发表时间：
1984-01-01
影响因子：
15.9
通讯作者：
BERRY, CA
中科院分区：
文献类型：
--
作者：
BAUM, M;BERRY, CA
在离体灌流的家兔近曲小管（PCT）中研究了主动NaCl转运的电性质和基底外侧膜Cl-电导的意义。在对照期和恢复期，用模拟晚期近端肾小管液的高Cl-溶液灌注PCT，并将其浸泡在模拟兔血清的白蛋白溶液中。通过将肾小管浸泡在没有阴离子梯度的高Cl-白蛋白溶液中来检查NaCl转运的电性质。在控制期和恢复期的体积重吸收（Jv）为0.56和0.51 nl/mm·cnt。min，0.45 nl/mm.在高Cl-浴中浸泡30 min后，肾小管上皮细胞凋亡率明显降低。在控制和恢复期间的跨上皮电位差（PD）平均为2.3 mV，但在没有阴离子梯度的情况下降低至0.0 mV，这表明NaCl转运是电中性的。进一步的证据表明，NaCl运输是电中性的，通过检查的效果，0.01 mM哇巴因在PCT灌注和高氯离子溶液浴。Jv为0.54 nl/mm. cnt。在控制期内，与抑制主动转运后的零无统计学差异。两个阶段的PD与0无差异。两组研究探讨了基底外侧膜Cl-电导在NaCl转运中的作用。去极化基底外侧膜与2 mM浴Ba 2+没有显着影响Jv或PD。研究了假定的Cl-电导抑制剂蒽-9-CO_2H的作用。蒽-9-CO2 H对Jv和PD无显著影响。数据表明，氯化钠转运在PCT是电中性和跨细胞的，并提供证据反对一个显着的作用，基底外侧膜氯电导在兔PCT。
The electrical nature of active NaCl transport and the significance of a basolateral membrane Cl- conductance were examined in isolated perfused rabbit proximal convoluted tubules (PCT). PCT were perfused with a high Cl- solution that simulated late proximal tubular fluid and were bathed in an albumin solution that simulated rabbit serum in the control and recovery periods. The electrical nature of NaCl transport was examined by bathing the tubules in a high Cl- albumin solution where there were no anion gradients. Volume reabsorption (Jv) during the control and recovery period was 0.56 and 0.51 nl/mm .cntdot. min, respectively, and 0.45 nl/mm .cntdot. min when the tubules were bathed in a high Cl- bath. The transepithelial potential difference (PD) during the control and recovery periods averaged 2.3 mV, but decreased to 0.0 mV in the absence of anion gradients, which indicated that NaCl transport is electroneutral. Further evidence that NaCl transport is electroneutral was obtained by examining the effect of addition of 0.01 mM ouabain in PCT perfused and bathed with high Cl- solutions. The Jv was 0.54 nl/mm .cntdot. min in the control period and not statistically different from zero after inhibition of active transport. The PD was not different from 0 in both periods. Two groups of studies examined the role of basolateral membrane Cl- conductance in NaCl transport. Depolarizing the basolateral membrane with 2 mM bath Ba2+ did not significantly affect Jv or PD. The effect of the presumptive Cl- conductance inhibitor anthracene-9-CO2H was examined. Anthracene-9-CO2H did not significantly affect Jv or PD. The data show that NaCl transport in the PCT is electroneutral and transcellular and provide evidence against a significant role for basolateral membrane Cl- conductance in the rabbit PCT.