Barber R D, Woolf A S, Henderson R M
Department of Pharmacology, University of Cambridge, UK.
Biochim Biophys Acta. 1995 Nov 30;1269(3):267-74. doi: 10.1016/0167-4889(95)00131-5.
The chloride conductance of conditionally immortalized mesangial cells isolated from the H-2Kb-tsA58 transgenic mouse was studied in cells grown in permissive and non-permissive culture conditions. No differences were found in the magnitude of the chloride conductance in 140 mM tetramethyl ammonium chloride between cells grown in permissive and non-permissive culture conditions (1.08 +/- 0.05 nS and 1.02 +/- 0.05 nS). Selectivity sequences were defined as 1.8I- > 1.2Br- > lCl- and 1.3I- > 1.1Br- > lCl- respectively and both the anion channel inhibitors niflumic acid and ochratoxin A inhibited the chloride conductance in a dose-dependent manner. The chloride conductance was made up from calcium-dependent and calcium-independent components and in the presence of 1 microM free calcium in the pipette this could be increased by the presence of 100 U ml-1 insulin added to the incubation medium. This appeared to increase the sensitivity of the conductance to levels of intracellular calcium as no differences were observed in the presence of either 1 mM or 100 nM pipette calcium. These data indicate that there is a significant chloride conductance in mesangial cells from the H-2Kb-tsA58 transgenic mouse and minimal changes are observed with changes from permissive to non-permissive culture conditions.
研究了从H-2Kb-tsA58转基因小鼠分离的条件永生化系膜细胞在允许和非允许培养条件下生长时的氯电导。在140 mM四甲基氯化铵中，允许培养条件和非允许培养条件下生长的细胞之间的氯电导大小没有差异（分别为1.08±0.05 nS和1.02±0.05 nS）。选择性序列分别定义为1.8I⁻＞1.2Br⁻＞Cl⁻和1.3I⁻＞1.1Br⁻＞Cl⁻，阴离子通道抑制剂氟尼辛和赭曲霉毒素A均以剂量依赖性方式抑制氯电导。氯电导由钙依赖性和钙非依赖性成分组成，在移液管中存在1 μM游离钙的情况下，向孵育培养基中添加100 U/ml胰岛素可增加氯电导。这似乎增加了电导对细胞内钙水平的敏感性，因为在移液管中存在1 mM或100 nM钙的情况下未观察到差异。这些数据表明，H-2Kb-tsA58转基因小鼠的系膜细胞存在显著的氯电导，并且从允许培养条件转变为非允许培养条件时观察到的变化极小。
