NEUROSCIENCES AND NEUROANAESTHESIA Dexmedetomidine, an a 2 -adrenergic agonist, inhibits neuronal delayed-rectifier potassium current and sodium current
NEUROSCIENCES AND NEUROANAESTHESIA Dexmedetomidine, an a 2 -adrenergic agonist, inhibits neuronal delayed-rectifier potassium current and sodium current
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神经科学和神经麻醉右美托咪定是一种α2-肾上腺素能激动剂，可抑制神经元延迟整流钾电流和钠电流
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
T. Chi
中科院分区：
文献类型：
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作者：
H. Peng;S. ;B. Dalin;T. Chi
结果。地塞米松抑制NG108-15细胞延迟整流钾电流[IK(DR)]的幅度呈浓度依赖性，IC50值为4.6 mM。在DEX的存在下，IK(DR)的稳态失活没有明显变化。最小结合方案也被用来评估地塞米松诱导的IK阻断(DR)。在育亨宾(10 MM)或依福生(10 MM)预先孵育的细胞中，仍观察到地塞米松对IK(DR)的抑制。地塞米松使钠电流峰值(INa)降低，但对L型钙电流影响不大。在电流钳结构下，DEX延长了动作电位的时程。对AP波反应的IK(DR)和INA对地塞米松的阻断比矩形脉冲诱发的更敏感。在分离的小脑颗粒细胞中，地塞米松也能有效地抑制IK(DR)。结论。地塞米松的作用并不局限于它与2-肾上腺素能受体的相互作用。地塞米松及其结构相关化合物对IK(DR)和INA的抑制作用可能是其影响体内神经元活动的潜在机制之一。
Results. DEX suppressed the amplitude of delayed rectifier K current [IK(DR)] in a concentration-dependent manner with an IC50 value of 4.6 mM in NG108-15 cells. No change in the steady-state inactivation of IK(DR) was evident in the presence of DEX. A minimal binding scheme was also used to evaluate DEX-induced block of IK(DR). Inhibition of IK(DR) by DEX was still observed in cells preincubated with yohimbine (10 mM) or efaroxan (10 mM). DEX depressed the peak amplitude of Na current (INa), whereas it had minimal effect on L-type Ca current. Under current-clamp configuration, DEX increased the duration of action potentials (APs). IK(DR) and INa in response to AP waveforms were more sensitive to block by DEX than those elicited during rectangular pulses. In isolated cerebellar granule cells, DEX also effectively suppressed IK(DR). Conclusions. The effects of DEX are not limited to its interactions with a2-adrenergic receptors. Inhibitory effects on IK(DR) and INa constitute one of the underlying mechanisms through which DEX and its structurally related compounds might affect neuronal activity in vivo.
影响因子：
7
作者：
通讯作者：
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