An electrophysiological technique to measure change in hepatocyte water volume.
An electrophysiological technique to measure change in hepatocyte water volume.
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一种测量肝细胞水量变化的电生理技术。
DOI：
10.1016/0005-2736(90)90435-q
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
R. Wondergem
中科院分区：
文献类型：
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作者：
W. Khalbuss;R. Wondergem
我们应用了电生理技术（Reuss L.等人（1985）Proc. Acad. Sci. USA 82，6014）以测量渗透应激期间稳态肝细胞体积的变化。小鼠肝切片中的肝细胞在短暂暴露于制霉菌素期间负载有四甲基铵离子（TMA+）。细胞内TMA+活性（α i TMA）用TMA+敏感的双管微电极测量。用TMA+加载肝细胞不改变其膜电位（Vm），并且在稳态条件下，在单次穿刺中α i TMA在4 min内保持恒定。高渗溶液（向培养基中加入50、100和150 mM蔗糖）和低渗溶液（将培养基中的蔗糖减少50和100 mM）分别增加和减少α i TMA，这证明了跨膜水运动。稳态细胞水体积变化曲线的斜率[（α i TMA）O/（α i TMA）4 min]− 1与培养基相对渗透压摩尔浓度（实验mosmol/对照mosmol）− 1的关系小于理想渗透压计的预测值。相应的Vm测量结果表明，其幅度增加与低渗透压和高渗透压降低。在0.66× 286 mosmol低渗胁迫（对照）中加入Ba 2+（2 mM）时，细胞含水量增加1.44±0.02倍，而单独低渗胁迫仅增加1.12±0.02倍，P< 0.001。Ba 2+也使低渗应激的超极化由1.62±0.04降低到1.24±0.09，P< 0.01。我们的结论是肝细胞部分调节其稳态体积在低和高渗应激。然而，容量调节在低渗应激减少沿着与超极化的Vm的存在下的K+通道阻滞剂，Ba 2+。这表明，在渗透胁迫期间V m的变化为肝细胞体积调节提供了间流电动势。
We have applied an electrophysiologic technique (Reuss L.(1985) Proc. Natl. Acad. Sci. USA 82, 6014) to measure changes in steady-state hepatocyte volume during osmotic stress. Hepatocytes in mouse liver slices were loaded with tetramethylammonium ion (TMA+) during transient exposure of cell to nystatin. Intracellular TMA+ activity (α i TMA) was measured with TMA+-sensitive, double-barrelled microelectrodes. Loading hepatocytes with TMA+ did not change their membrane potential (V m), and under steady-state conditions α i TMA remained constant over 4 min in a single impalement. Hyperosmotic solutions (50, 100 and 150 mM sucrose added to media) and hyposmotic solutions (sucrose in media reduced by 50 and 100 mM) increased and decreased α i TMA, respectively, which demonstrated transmembrane water movements. The slope of the plot of change in steady-state cell water volume,[(α i TMA) O/(α i TMA) 4 min]− 1, on the relative osmolality of media,(experimental mosmol/control mosmol)− 1, was less than predicted for a perfect osmometer. Corresponding measurements of V m showed that its magnitude increased with hyposmolality and decreased with hyperosmolality. When Ba 2+(2 mM) was present during hyposmotic stress of 0.66× 286 mosmol (control), cell water volume increased by a factor of 1.44±0.02 compared with that of hyposmotic stress alone, which increased cell water volume by a factor of only 1.12±0.02, P< 0.001. Ba 2+ also decreased the hyperpolarization of hyposmotic stress from a factor of 1.62±0.04 to 1.24±0.09, P< 0.01. We conclude that hepatocytes partially regulate their steady-state volume during hypo-and hyperosmotic stress. However, volume regulation during hyposmotic stress diminished along with hyperpolarization of V m in the presence of the K+-channel blocker, Ba 2+. This shows that variation in V m during osmotic stress provides an intercurrent, electromotive force for hepatocyte volume regulation.
用微电极测量小鼠肝脏切片中细胞内氯离子的活性。
DOI：
10.1016/0005-2736(87)90155-6
发表时间：
1987
期刊：
Biochimica et biophysica acta
影响因子：
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作者：
Lyall,V;Croxton,TL;Armstrong,WM
通讯作者：
Armstrong,WM