New selective inhibitors of calcium-activated chloride channels-T16Ainh-A01, CaCCinh-A01 and MONNA - what do they inhibit?
New selective inhibitors of calcium-activated chloride channels-T16Ainh-A01, CaCCinh-A01 and MONNA - what do they inhibit?
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DOI：
10.1111/bph.13201
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发表时间：
2015-08-01
影响因子：
7.3
通讯作者：
Andersson, K. E.
中科院分区：
文献类型：
--
作者：
Boedtkjer, D. M. B.;Kim, S.;Andersson, K. E.
背景与目的T16 A（inh）-A01、CaCCinh-A01和MONNA被鉴定为TMEM 16 A钙激活氯离子通道（CaCC）的选择性抑制剂。本研究的目的是检查这些化合物对分离的阻力动脉中存在和不存在（）的胞外chloride.Experimental ApproachIsolated阻力动脉保持在myograph和张力记录，在某些情况下结合微电极穿刺膜电位测量或细胞内钙监测使用Fura-2。电压依赖性钙电流（VDCC）在A7 r5细胞中用电压钳电生理学方法测量，使用钡作为电荷载体。Key ResultsThe rodent arteries preconstructed with noradrenaline or U46619 are concentration-dependently relaxed by T16 A（inh）-A01（0.1- 10 M）：在+/-氯离子中，IC 50和最大松弛等效（30分钟天冬氨酸替代）和T16 A（inh）-A01诱导的血管舒张+/-氯伴随着膜超极化和细胞内钙降低。然而，激动剂浓度-反应曲线+/-氯，与10 M T16 A（注射）-A01存在，实现了类似的最大收缩，虽然激动剂敏感性降低。T16 A（inh）-A01 +/-氯化物浓度依赖性地舒张由升高的细胞外钾诱导的收缩。此外，T16 A（inh）-A01以浓度依赖性方式抑制A7 r5细胞中的VDCC。CaCCinh-A01和MONNA（0.1- 10 M）诱导血管舒张+/-氯，并且两种化合物均降低最大收缩性。MONNA，10 M，诱导大量的膜hyperpolarization under resting conditions.Conclusions and ImplicationsT 16 A（inh）-A01，CaCCinh-A01和MONNA浓度依赖性地放松啮齿动物的阻力动脉，但当跨膜氯离子梯度被废除时，发生等效的血管舒张与inpermeant阴离子。因此，这些化合物在抑制分离的电导的浓度范围内显示出对TMEM 16 A的不良选择性和对血管组织中CaCC的抑制。
Background and PurposeT16A(inh)-A01, CaCCinh-A01 and MONNA are identified as selective inhibitors of the TMEM16A calcium-activated chloride channel (CaCC). The aim of this study was to examine the chloride-specificity of these compounds on isolated resistance arteries in the presence and absence () of extracellular chloride.Experimental ApproachIsolated resistance arteries were maintained in a myograph and tension recorded, in some instances combined with microelectrode impalement for membrane potential measurements or intracellular calcium monitoring using fura-2. Voltage-dependent calcium currents (VDCC) were measured in A7r5 cells with voltage-clamp electrophysiology using barium as a charge carrier.Key ResultsRodent arteries preconstricted with noradrenaline or U46619 were concentration-dependently relaxed by T16A(inh)-A01 (0.1-10M): IC50 and maximum relaxation were equivalent in +/- chloride (30min aspartate substitution) and the T16A(inh)-A01-induced vasorelaxation +/- chloride were accompanied by membrane hyperpolarization and lowering of intracellular calcium. However, agonist concentration-response curves +/- chloride, with 10M T16A(inh)-A01 present, achieved similar maximum constrictions although agonist-sensitivity decreased. Contractions induced by elevated extracellular potassium were concentration-dependently relaxed by T16A(inh)-A01 +/- chloride. Moreover, T16A(inh)-A01 inhibited VDCCs in A7r5 cells in a concentration-dependent manner. CaCCinh-A01 and MONNA (0.1-10M) induced vasorelaxation +/- chloride and both compounds lowered maximum contractility. MONNA, 10M, induced substantial membrane hyperpolarization under resting conditions.Conclusions and ImplicationsT16A(inh)-A01, CaCCinh-A01 and MONNA concentration-dependently relax rodent resistance arteries, but an equivalent vasorelaxation occurs when the transmembrane chloride gradient is abolished with an impermeant anion. These compounds therefore display poor selectivity for TMEM16A and inhibition of CaCC in vascular tissue in the concentration range that inhibits the isolated conductance.