摘要
目的研究大鼠背根神经节(DRG)细胞酸感受离子通道(ASICs)的电生理学和药理学特性。方法应用全细胞膜片钳技术,在急性分散的成年大鼠DRG细胞上记录并分析由不同浓度H+(降低pH值)诱发的ASICs电流。结果在266个大鼠DRG神经元上记录到由H+诱发的3种不同类型的ASICs电流,分别为ASIC1样电流(n=66,24·8%)、ASIC2样电流(n=81,30·4%)和ASIC3样电流(n=119,44·7%)。ASIC1样电流具有快速失活成份,衰减快;ASIC2样电流具有稳态失活成份,衰减十分缓慢;而ASIC3样电流具有快速失活与稳态失活双相成份。三者均不具有整流现象。此3种电流对细胞外H+表现出不同的敏感性,H+诱发电流的pH50分别是:ASIC1-like,pH5·82;ASIC2-like,pH5·18;ASIC3-like,pH6·24。氨氯吡咪以浓度依赖性方式可逆性阻断大鼠DRG神经元的ASICs,对3种ASICs电流的抑制效应差异有显著性。其IC50分别为:ASIC1-like,19·86μmol·L-1;ASIC2-like,42·73μmol·L-1;ASIC3-like,27·91μmol·L-1。结论成年大鼠DRG神经元细胞上表达了3种不同类型的ASICs,且其在表达率、H+敏感性、失敏以及氨氯吡咪敏感性等方面差异均有显著性。
Aim To study electrophysiological and pharmacological properties of acid-sensing ion channels （ASICs） in rat dorsal root ganglia （DRG） neurons. Methods ASICs currents evoked by extracellular so- lutions of various pH values were recorded and analyzed in acute isolated rat DRG neurons by using whole-cell patch clamp technique. Result Three types of ASICs currents were recorded in 266 DRG neurons, which were named as ASIC1-like （n = 66, 24. 8% ）, ASIC2-like （ n = 81, 30. 4% ） and ASIC3-like （ n = 119, 44. 7% ）, respectively. ASIC1-like currents had transient component and attenuated quickly. ASIC2- like currents had sustained component and attenuated very slowly. ASIC3-like currents had both transient and sustained component. And these three ASICs currents had no rectification. There were distinguished disparities on H^＋ sensitivity among them; their pH50 values were was ASIC1-like, pH 5. 82; ASIC2-like, pH 5.18 ; ASIC3-like, pH 6. 24, respectively. Amiloride reversibly blocked ASICs in a concentration-dependant manner. There are distinguished disparities among the depressive effects of amiloride on three types of ASICs currents. Their IC50 values were was ASIC1-like, 19. 86μmol·L^-1 ; ASIC2-like, 42.73 μmol·L^-1 ; ASIC3-like, 27.91μmol·L^-1, respectively. Conclusion Three types of ASICs are expressed in rat DRG neurons. And their properties of expression rate, H^＋ sensitivity, desensitization, and inhibitory effects of amiloride were significantly distinct.
出处
《中国药理学通报》
CAS
CSCD
北大核心
2007年第1期33-37,共5页
Chinese Pharmacological Bulletin
基金
国家自然科学基金面上资助项目(No30472019)
关键词
酸感受离子通道
背根神经节
全细胞膜片钳
氨氯吡咪
acid-sensing ion channel （ASIC）
dorsal root ganglia （DRG）
whole-cell patch clamp
amiloride
