期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1980
卷号：77
期号：12
页码：7458-7462
DOI：10.1073/pnas.77.12.7458
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：To evaluate [3H]phencyclidine ([3H]PCP)as a probe for the ionic channel of the nicotinic receptor, the characteristics of its binding to electric organ membranes od Torpedo ocellata and its effects on frog sartorius muscle were studied. Similar to PCP, [3H]PCP depressed the peak amplitude of endplate current, caused nonlinearity in the voltage-current relationship at negative potentials, accelerated the decay time of the end-plate current, and shortened the channel lifetime. Thus, [3H]PCP interacted with the ionic channel of the nicotinic receptor, although there were a few differences between its effect and that of PCP. Binding of [3H]PCP to Torpedo membranes was to sites on the ionic channel of acetylcholine (AcCho) receptor because it was saturable, dependent upon protein concentration, and inhibited by drugs that interact with the ionic channel, and the initial rate of binding was potentiated by receptor agonists. Equilibrium binding of [3H]PCP to Torpedo membranes was with two affinities, but in the presence of AcCho, [3H]PCP binding was with a single affinity. The affinities of channel drugs obtained by inhibition of binding of [3H]PCP and [3H[perhydrohistrionicotoxin to Torpedo membranes were different, with correlation coefficients of 0.52 and 0.82 in the absence and presence of a receptor agonist, respectively; this suggests differences in their binding sites on the ionic channel of the AcCho receptor.
