Electrogenic Na+/K+-transport in human endothelial cells
Electrogenic Na+/K+-transport in human endothelial cells
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人内皮细胞中的电钠/钾转运
DOI：
10.1007/bf00384356
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
B. Nilius
中科院分区：
文献类型：
--
作者：
M. Oike;G. Droogmans;R. Casteels;B. Nilius
采用全细胞膜片钳技术和制霉菌素穿孔膜片钳技术，结合Fura-2/AM测定细胞内钙离子浓度（[Ca ~（2+）]i），测定了人脐静脉内皮细胞的Na ~+/K ~+泵电流。用40 mmol/l [Na+]通过贴片移液管加载内皮细胞未引起[Ca 2 +]i的显著变化。用无K+溶液超灌注细胞也没有显着影响[Ca 2 +]i。在用无K+的溶液灌注细胞后再应用K+诱导在0 mV的保持电位下的外向电流。该电流几乎完全被100 μmol/l二氢哇巴因（DHO）阻断，因此被鉴定为Na+/K+泵电流。在Na+/K+泵的阻断和再激活期间，未观察到[Ca 2 +]i的变化。DHO浓度依赖性地阻断泵电流。半数最大抑制浓度为21 μmol/l。该值大于其他组织报告的值，阻滞几乎不可逆。胰岛素（10-1000 U/l）不影响泵电流。细胞内Na+浓度（[Na+]i）的增加增强了泵电流的幅度。[Na+]i对泵电流的半最大激活发生在约60 mmol/l。细胞外K ~+激活的半数浓度为2.4± 1.2mmol/l，Tl ~+和NH ~（4+）激活的半数浓度分别为0.4±0.1和8.7± 0.7mmol/l。通过施加线性电压斜坡获得了DHO敏感电流的电压依赖性。其反转电位比-150 mV更负。用传统的全细胞技术测量的泵电流比用制霉菌素穿孔贴片方法记录的泵电流小约四倍。然而，如果在移液器溶液中加入100 μmol/l鸟苷5′-O-（3-硫代三磷酸）（GTPγS），则在破裂全细胞模式下测得的电流与穿孔膜片技术测得的电流无显著差异。我们假设，使用穿孔补丁技术，防止冲洗出的鸟嘌呤核苷酸结合蛋白（G蛋白）连接的细胞内调节，这是必要的泵激活。
Na+/K+ pump currents were measured in endothelial cells from human umbilical cord vein using the whole-cell or nystatin-perforated-patch-clamp technique combined with intracellular calcium concentration ([Ca2+]i) measurements with Fura-2/AM. Loading endothelial cells through the patch pipette with 40 mmol/l [Na+] did not induce significant changes of [Ca2+]i. Superfusing the cells with K+-free solutions also did not significantly affect [Ca2+]i. Reapplication of K+ after superfusion of the cells with K+-free solution induced an outward current at a holding potential of 0 mV. This current was nearly completely blocked by 100 μmol/l dihydroouabain (DHO) and was therefore identified as a Na+/K+ pump current. During block and reactivation of the Na+/K+ pump no changes in [Ca2+]i could be observed. Pump currents were blocked concentration dependently by DHO. The concentration for half-maximal inhibition was 21 μmol/l. This value is larger than that reported for other tissues and the block was practically irreversible. Insulin (10–1000 U/l) did not affect the pump currents. An increase of the intracellular Na+ concentration ([Na+]i) enhanced the amplitude of the pump current. Half-maximal activation of the pump current by [Na+]i occurred at about 60 mmol/l. The concentration for half-maximal activation by extracellular K+ was 2.4±1.2 mmol/l, and 0.4±0.1 and 8.7±0.7 mmol/l for Tl+ and NH4+ respectively. The voltage dependence of the DHO-sensitive current was obtained by applying linear voltage ramps. Its reversal potential was more negative than −150 mV. Pump currents measured with the conventional whole-cell technique were about four times smaller than pump currents recorded with the nystatin-perforated-patch method. If however 100 μmol/l guanosine 5′-O-(3-thiotriphosphate) (GTPγS) were added to the pipette solution, the currents measured in the ruptured-whole-cell-mode were not significantly different from the currents measured with the perforated-patch technique. We suppose that the use of the perforated-patch technique prevents wash out of a guanine nucleotide-binding protein (G-protein)-connected intracellular regulator that is necessary for pump activation.
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阳离子载体升高牛内皮细胞血管紧张素转换酶并哇巴因抑制。
DOI：
10.1016/0167-4889(90)90168-d
发表时间：
1990
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Dasarathy,Y;Fanburg,BL
通讯作者：
Fanburg,BL
DOI：
--
发表时间：
1986
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Lynch,CJ;Wilson,PB;Blackmore,PF;Exton,JH
通讯作者：
Exton,JH
DOI：
10.1016/s0021-9258(19)39845-x
发表时间：
1990-02
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
R. Laskey;David John Adams;A. Johns;G. Rubanyi;C. van Breemen
通讯作者：
R. Laskey;David John Adams;A. Johns;G. Rubanyi;C. van Breemen
Ca 和细胞内蛋白质对 Na,K-ATP 酶的调节。
影响因子：
18.2
作者：
Yingst,DR
通讯作者：
Yingst,DR
哺乳动物心肌细胞中 Na-K 泵电流对内部 Na 的依赖性。
DOI：
10.1152/ajpheart.1990.259.2.h488
发表时间：
1990
期刊：
The American journal of physiology
影响因子：
--
作者：
Mogul,DJ;Singer,DH;TenEick,RE
通讯作者：
TenEick,RE