Descending vasa recta pericytes express voltage operated Na+ conductance in the rat.
Descending vasa recta pericytes express voltage operated Na+ conductance in the rat.
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大鼠中降直血管周细胞表达电压操作的Na电导。
DOI：
10.1113/jphysiol.2005.091538
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Pallone,ThomasL
中科院分区：
文献类型：
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作者：
Zhang,Zhong;Cao,Chunhua;Lee-Kwon,Whaseon;Pallone,ThomasL
我们研究了从肾外髓质分离的降直血管（DVR）周细胞电压操作的Na+电导特性。全细胞膜片钳记录显示去极化诱导的快速激活和快速灭活的内向电流，通过从细胞外缓冲液中去除Na+而不是Ca+而被消除。Na+电流（INa）对河豚毒素（TTX,Kd= 2.2 nm）高度敏感。在高浓度下，mibefradil （10 μm）和Ni+(1 mm)阻断了dina。对硝苯地平（10 μm）不敏感。L型Ca+通道激活剂FPL - 64176诱导缓慢激活/灭活的内向电流，该电流被硝苯地平消除。去极化至0 ~ 30 mV之间的膜电位诱导失活，时间常数为1 ms。膜电位在- 90和- 120 mV之间的复极化诱导失活恢复，时间常数为~ 11 ms。半最大值激活和失活分别发生在- 23.9和- 66.1 mV，斜率因子分别为4.8和9.5 mV。Na+通道活化剂veratridine （100 μm）可降低Na+通道内峰，防止失活。我们得出结论，与其他平滑肌细胞相似，TTX敏感电压操作的Na+电导在DVR周细胞中表达。
We studied the properties of a voltage‐operated Na+conductance in descending vasa recta (DVR) pericytes isolated from the renal outer medulla. Whole‐cell patch‐clamp recordings revealed a depolarization‐induced, rapidly activating and rapidly inactivating inward current that was abolished by removal of Na+but not Ca+from the extracellular buffer. The Na+current (INa) is highly sensitive to tetrodotoxin (TTX,Kd= 2.2 nm). At high concentrations, mibefradil (10 μm) and Ni+(1 mm) blockedINa.INawas insensitive to nifedipine (10 μm). The L‐type Ca+channel activator FPL‐64176 induced a slowly activating/inactivating inward current that was abolished by nifedipine. Depolarization to membrane potentials between 0 and 30 mV induced inactivation with a time constant of ∼1 ms. Repolarization to membrane potentials between −90 and −120 mV induced recovery from inactivation with a time constant of ∼11 ms. Half‐maximal activation and inactivation occurred at −23.9 and −66.1 mV, respectively, with slope factors of 4.8 and 9.5 mV, respectively. The Na+channel activator, veratridine (100 μm), reduced peak inwardINaand prevented inactivation. We conclude that a TTX‐sensitive voltage‐operated Na+conductance, with properties similar to that in other smooth muscle cells, is expressed by DVR pericytes.