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：1978
卷号：75
期号：9
页码：4563-4567
DOI：10.1073/pnas.75.9.4563
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Incubation of membrane fragments bearing acetylcholine receptors from Torpedo californica under an atmosphere of 3% halothane, 1% chloroform, or 6% diethyl ether greatly facilitates the carbamoylcholine-induced structural transition of the acetylcholine receptor reflected by alterations in the rate of binding of 125I-labeled -bungarotoxin. The half-time of this ligand-induced conformational change is decreased to 10% of the original value after incubation of the membranes with these volatile anesthetics at or near their clinical concentrations. The synergistic effects observed with the general anesthetics and carbamoylcholine are abolished if the membranes are incubated under a stream of air after exposure to the inhalational agents. The antagonist d-tubocurarine exerts a smaller yet measurable time-dependent effect on the toxin-binding properties of the membrane fragments. Treatment of membranes with general anesthetics facilitates this antagonist-induced conversion of the receptor protein as well. The synergism between ligands and general anesthetics may be due to the disruption by these inhalational agents of interactions at the protein-lipid interface, which may play a significant role in determination of receptor conformation. In addition, if the conformational change induced by carbamoylcholine observed in the snake toxin binding assay corresponds to desensitization of the receptor in vivo, facilitation of this conformational change by volatile anesthetics provides an attractive model for the pharmacological action of these compounds.
关键词：mechanism of general anesthesia ; ligand-induced conformational change ; protein-lipid interactions
