Open channel block and alteration of N-methyl-D-aspartic acid receptor gating by an analog of phencyclidine.
Open channel block and alteration of N-methyl-D-aspartic acid receptor gating by an analog of phencyclidine.
复制标题
苯环己哌啶类似物的开放通道阻断和 N-甲基-D-天冬氨酸受体门控的改变。
DOI：
10.1016/s0006-3495(98)77622-2
复制
发表时间：
1998
影响因子：
3.4
通讯作者：
Johnson,JW
中科院分区：
文献类型：
--
作者：
Dilmore,JG;Johnson,JW
本文研究了苯环利定（PCP）的结构类似物N-乙基-1，4，9，9 α-四氢-4 αR-cis-4αH-fluoren-4α-胺（NEFA）对N-甲基-d-天冬氨酸（NMDA）受体通道复合物的抑制作用。使用全细胞记录技术，我们证明NEFA抑制NMDA反应，在-66mV的IC 50为0.51μM。我们确定NEFA与开放通道结合，随后通道可以关闭并捕获阻断剂。一旦通道关闭，NEFA就无法分离，直到通道重新打开。单通道记录显示，NEFA以浓度依赖性方式减少单个NMDA激活通道的平均开放时间，前向阻断率（k+）为39.9μM− 1 s −1。NEFA的拮抗作用的计算模型的开发和约束使用单通道数据的动力学测量。通过多个标准，只有通道中的阻断剂结合导致受体操作变化的模型才能充分拟合或预测全细胞数据。通过比较模型预测和实验测量的NEFA行动在一个高的NMDA浓度，我们确定，NEFA通过影响通道门控影响受体的运作。我们的结论是抑制NMDA受体的PCP样阻滞剂涉及修改通道门控以及通过开放通道的电流阻断。
We investigated inhibition of theN-methyl-d-aspartic acid (NMDA) receptor-channel complex byN-ethyl-1,4,9,9α-tetrahydro-4αR-cis-4αH-fluoren-4α-amine (NEFA), a structural analog of phencyclidine (PCP). Using the whole-cell recording technique, we demonstrated that NEFA inhibits NMDA responses with an IC50of 0.51μM at −66mV. We determined that NEFA binds to the open channel, and subsequently the channel can close and trap the blocker. Once the channel has closed, NEFA is unable to dissociate until the channel reopens. Single-channel recordings revealed that NEFA reduces the mean open time of single NMDA-activated channels in a concentration-dependent manner with a forward blocking rate (k+) of 39.9μM−1s−1. A computational model of antagonism by NEFA was developed and constrained using kinetic measurements of single-channel data. By multiple criteria, only models in which blocker binding in the channel causes a change in receptor operation adequately fit or predicted whole-cell data. By comparing model predictions and experimental measurements of NEFA action at a high NMDA concentration, we determined that NEFA affects receptor operation through an influence on channel gating. We conclude that inhibition of NMDA receptors by PCP-like blockers involves a modification of channel gating as well as block of current flow through the open channel.