Activation of muscle nicotinic acetylcholine receptor channels by nicotinic and muscarinic agonists
Activation of muscle nicotinic acetylcholine receptor channels by nicotinic and muscarinic agonists
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DOI：
10.1038/sj.bjp.0702941
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发表时间：
1999-12-01
影响因子：
7.3
通讯作者：
Auerbach, A
中科院分区：
文献类型：
--
作者：
Akk, G;Auerbach, A
1测定了重组小鼠成体神经肌肉乙酰胆碱受体通道（nAChR）被氨甲酰胆碱、尼古丁、毒蕈碱和氧化震颤素激活的量效参数。通过单通道动力学分析估计激动剂结合和解离以及通道打开和关闭的速率常数。2解离平衡常数为（mM）：乙酰胆碱（0.16）尼古丁（0.5）>毒蕈碱（0.15）。4大鼠神经元α（4）β（2）nAChR可被所有激动剂激活。然而，详细的动力学分析是不可能的，因为记录缺乏集群代表一个单一的受体复合物的活动。因此，贴片中的通道数量未知，并且无法确定激活速率常数。5考虑到受体亲和力和激动剂功效，毒蕈碱和氧震颤碱是肌肉型nAChR的显著激动剂。结果进行了讨论，在nAChR发射结合位点的结构-功能关系。
1 The dose-response parameters of recombinant mouse adult neuromuscular acetylcholine receptor channels (nAChR) activated by carbamylcholine, nicotine, muscarine and oxotremorine were measured. Rate constants for agonist association and dissociation, and channel opening and closing, were estimated from single-channel kinetic analysis.2 The dissociation equilibrium constants were (mM): ACh (0.16)nicotine (0.5)>muscarine (0.15).4 Rat neuronal alpha(4)beta(2) nAChR can be activated by all of the agonists. However, detailed kinetic analysis was impossible because the recordings lacked clusters representing the activity of a single receptor complex. Thus, the number of channels in the patch was unknown and the activation rate constants could not be determined.5 Considering both receptor affinity and agonist efficacy, muscarine and oxotremorine are significant agonists of muscle-type nAChR. The results are discussed in terms of structure-function relationships at the nAChR transmitter binding site.