Conductive properties of the rabbit outer medullary collecting duct: inner stripe.
Conductive properties of the rabbit outer medullary collecting duct: inner stripe.
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兔外髓集合管的导电特性：内条纹。
DOI：
10.1152/ajprenal.1985.248.4.f500
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Koeppen,BM
中科院分区：
文献类型：
--
作者：
Koeppen,BM
从家兔肾内条切取外髓集合管段，进行体外灌注。通过电缆分析和细胞内电压记录微电极测定了肾小管上皮细胞和单个细胞膜的导电性能。在35个小管中，跨上皮电压（VT）和电阻（RT）平均值分别为17.2 +/- 1.4 mV（管腔阳性）和58.6 +/- 5.3 k Ω X cm。基底外侧膜电压（Vbl）为-29.2 +/- 2.1 mV（n = 23）。顶端细胞膜不含可感知的离子电导，如顶端细胞膜部分电阻（fRa = Ra/Ra + Rb）的高值所证明的，其接近1（0.99 +/- 0.01; n = 23）。此外，除了阿米洛利或氯化钡的小管腔是没有影响的电特性的细胞，是一个两倍的减少管腔[Cl-]。基底外侧细胞膜的导电性能进行了评估与浴离子取代。电解液[Cl-]降低两倍使Vbl去极化14.7 +/- 0.4 mV（理论值，17 mV），而电解液[K+]增加10倍仅导致0.9 +/- 0.4 mV去极化（理论值，61 mV）。用四甲基铵（从150至75 mM）替代浴Na+没有效果。还原浴[HCO-3]从25 mM降至5 mM（恒定PCO 2）导致Vbl的稳态去极化为8.4 +/- 0.4 mV，这不能归因于传导性HCO-3运动。因此，基底外侧细胞膜主要是Cl-选择性的。（250字处删节）
Segments of outer medullary collecting duct were dissected from the inner stripe of the rabbit kidney (OMCDi) and perfused in vitro. The conductive properties of the tubule epithelium and individual cell membranes were determined by means of cable analysis and intracellular voltage-recording microelectrodes. In 35 tubules the transepithelial voltage (VT) and resistance (RT) averaged 17.2 +/- 1.4 mV, lumen positive, and 58.6 +/- 5.3 k omega X cm, respectively. The basolateral membrane voltage, (Vbl) was -29.2 +/- 2.1 mV (n = 23). The apical cell membrane did not contain appreciable ion conductances, as evidenced by the high values of apical cell membrane fractional resistance (fRa = Ra/Ra + Rb), which approached unity (0.99 +/- 0.01; n = 23). Moreover, addition of amiloride or BaCl2 to the tubule lumen was without effect on the electrical characteristics of the cell, as was a twofold reduction in luminal [Cl-]. The conductive properties of the basolateral cell membrane were assessed with bath ion substitutions. A twofold reduction in bath [Cl-] depolarized Vbl by 14.7 +/- 0.4 mV (theoretical, 17 mV), while a 10-fold increase in bath [K+] resulted in only a 0.9 +/- 0.4 mV depolarization (theoretical, 61 mV). Substituting bath Na+ with tetramethylammonium (from 150 to 75 mM) was without effect. Reducing bath [HCO-3] from 25 to 5 mM (constant PCO2) resulted in a steady-state depolarization of Vbl of 8.4 +/- 0.4 mV that could not be attributed to conductive HCO-3 movement. Thus, the basolateral cell membrane is predominantly Cl- selective.(ABSTRACT TRUNCATED AT 250 WORDS)