Extracellular trypsin increases ASIC1a selectivity for monovalent versus divalent cations
Extracellular trypsin increases ASIC1a selectivity for monovalent versus divalent cations
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DOI：
10.1016/j.jneumeth.2004.11.012
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发表时间：
2005-06-15
影响因子：
3
通讯作者：
Flonta, ML
中科院分区：
文献类型：
--
作者：
Neaga, E;Amuzescu, B;Flonta, ML
Sustained proton activation of native ASIC channels in primary sensory neurons or HEK293 cells leads to a reduction in the peak amplitude of transient inward currents and the progressive development of a persistent component, which hinders titration experiments in pharmacological studies. Here we report that extracellular trypsin applied for 5 min at 10-45 mu g/ml and/or a short exposure to high Ca2+ (75 mM for less than I min) alleviate the persistent component, improving reproducibility of acid-elicited transients. Selectivity measurements performed in current clamp mode, in essentially bi-ionic conditions, prove that these two treatments decrease hASIC1 a permeability for divalent but not for monovalent cations, producing a significant change in P-Na/P-Ca from 8.2 +/- 2.1 (mean +/- S.D.) to 26.0 +/- 17.8 (trypsin) or 24.5 +/- 11.1 (high Ca2+). The slope conductance of the unit inward Ca2+ transient was also lowered from 5.7 to 2.7 pS after trypsin. (c) 2004 Elsevier B.V. All rights reserved.
