Apical K+ conductance in maturing rabbit principal cell.
Apical K+ conductance in maturing rabbit principal cell.
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成熟兔主细胞的顶端 K 电导。
DOI：
10.1152/ajprenal.1997.272.3.f397
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Palmer,LG
中科院分区：
文献类型：
--
作者：
Satlin,LM;Palmer,LG
从新生兔分离的皮质集合管（CCD）和灌注在体外没有检测到净K+分泌。为了确定新生儿主细胞的低顶端K+渗透性是否限制了生命早期的K+分泌，我们使用膜片钳技术在分离自成熟兔的裂开式CCD中研究主细胞中传导K+通道的性质和密度。在移液器中加入KCl，在浴中加入加热至37 ℃的NaCl溶液，在0%的细胞中观察到电导约为42 pS的内向电流。在1、2、3、4和5周龄动物中获得的细胞附着贴片分别为10%（0/13或0/13）、10%（2/21）、18%（5/28）、29%（4/14）和56%（10/18）。该通道的电导和反转电位使我们怀疑它代表了L. G.帕尔默湖，澳-地Antonian和G. Frindt（J.Gen.Physiol.104：693-710，1994）。出生后，每个贴片的平均开放通道数（NPo）逐渐增加（P < 0.05），从1周时的0，到2周时的0.06 ± 0.04，到3周时的0.40 ± 0.18，到4周时的0.74 ± 0.41，到5周时的1.06 ± 0.28。NPo的增加似乎主要是由于N的发育增加，这是通道的数量;开放概率，Po，保持恒定在约0.5的所有通道后，第2周的生活。在出生后的生活中进行的K+通道的数量的增加可能有助于在CCD的净K+分泌的成熟增加。
Net K+ secretion is not detected in cortical collecting ducts (CCDs) isolated from newborn rabbits and perfused in vitro. To establish whether a low apical K+ permeability of the neonatal principal cell limits K+ secretion early in life, we used the patch-clamp technique in split-open CCDs isolated from maturing rabbits to study the properties and density of conducting K+ channels in principal cells. With KCl in the pipette and a NaCl solution warmed to 37 degrees C in the bath, inward currents with a conductance of approximately 42 pS were observed in 0% (0 out of 13 or 0/13), 10% (2/21), 18% (5/28), 29% (4/14), and 56% (10/18) of cell-attached patches obtained in 1-, 2-, 3-, 4-, and 5-wk-old animals, respectively. The conductance and reversal potential of this channel led us to suspect that it represented the low-conductance K+ channel previously described in the rat CCD by L. G. Palmer, L. Antonian, and G. Frindt (J. Gen. Physiol. 104: 693-710, 1994). The mean number of open channels per patch (NPo) increased progressively (P < 0.05) after birth, from 0 at 1 wk, to 0.06 +/- 0.04 at 2 wk, to 0.40 +/- 0.18 at 3 wk, to 0.74 +/- 0.41 at 4 wk, and to 1.06 +/- 0.28 at 5 wk. The increase in NPo appeared to be due primarily to a developmental increase in N, which is the number of channels; open probability, Po, remained constant at approximately 0.5 for all channels identified after the 2nd wk of life. The increase in number of conducting K+ channels during postnatal life is likely to contribute to the maturational increase in net K+ secretion in the CCDs.