BINDING OF ACETYLCHOLINE TO RECEPTORS AND ITS REMOVAL FROM SYNAPTIC CLEFT
BINDING OF ACETYLCHOLINE TO RECEPTORS AND ITS REMOVAL FROM SYNAPTIC CLEFT
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DOI：
10.1113/jphysiol.1973.sp010248
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发表时间：
1973-01-01
影响因子：
5.5
通讯作者：
MILEDI, R
中科院分区：
文献类型：
--
作者：
KATZ, B;MILEDI, R
1.用聚焦外微电极记录乙酰胆碱（ACh）噪声和微终板电位。2.研究了普罗斯的明对“分子”和“量子”递质作用时间进程的影响。普罗斯的明（10-6 g/ml）对分子“门控作用”的持续时间影响很小或没有影响，而它大大延长了量子电导的变化。3.在抑制乙酰胆碱水解后，递质从突触中的清除通常太慢，不能通过自由扩散来解释。这表明，扩散延迟结合突触后受体。这与箭毒或α-银环蛇毒素阻断受体缩短并减少量子递质作用的发现一致。4.受体阻断剂的相关影响，对微型终板电流的大小和时间过程，进行了简单的分析。结果表明，胆碱酯酶抑制后，约有三分之二的乙酰胆碱量子包与突触后受体结合。5.在局灶性外部记录过程中，由于似乎是一种压缩伪影，阻碍了发射器的向外扩散，因此普罗斯的明对微型终板电位时程的影响可能会被夸大。
1. Acetylcholine (ACh) noise and miniature end-plate potentials were recorded with focal external micro-electrodes. 2. The effect of prostigmine on the time course of the `molecular' and `quantal' transmitter actions was studied. Prostigmine (10-6 g/ml.) has little or no effect on the duration of the molecular `gating action', while it greatly prolongs the quantal conductance change. 3. After inhibition of ACh hydrolysis, the removal of the transmitter from the synapse is generally too slow to be accounted for by free diffusion. It is suggested that diffusion is delayed by binding to post-synaptic receptors. This is consistent with the finding that receptor blockage by curare or α-bungarotoxin shortens as well as reduces quantal transmitter action. 4. The correlated effects of the receptor-blocking agents, on size and time course of the miniature end-plate currents, were subjected to a simple analysis. Its result suggests that after inhibition of cholinesterase about two thrids of the quantal packet of ACh combines with post-synaptic receptors. 5. During focal external recording the effect of prostigmine on the time course of miniature end-plate potentials can become exaggerated due to what appears to be a compression artifact which obstructs outward diffusion of the transmitter.