RT Journal Article SR Electronic T1 NONMUSCARINIC STIMULATION AND BLOCK OF A SYMPATHETIC GANGLION BY 4-(m-CHLOROPHENYLCARBAMOYLOXY)-2-BUTYNYLTRIMETHYLAMMONIUM CHLORIDE (McN-A-343) JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 337 OP 345 VO 157 IS 2 A1 Jorge Jaramillo A1 Robert L. Volle YR 1967 UL http://jpet.aspetjournals.org/content/157/2/337.abstract AB Ganglionic firing produced by 4-(m-chlorophenylcarbamoyloxy)-2-butynyltrimethylammonium chloride (McN-A-343) in the cat superior cervical ganghion had two components: a late-occurring response that was prevented by atropine and an early-occurring response that was resistant to blockade by either hexamethonium (C6) or atropine. The discharge was accompanied by a sustained depolarization. Whereas small doses of McN-A-343 enhanced transmission, large doses caused ganglionic blockade. Atropine had no effect on the blocking actions of McN-A-343. Although the blockade by McN-A-343 was antagonized by tetanic pregangiionic stimulation, the block was not frequency-dependent. Ganglionic firing by KCl, acetylcholine or tetramethylammonium was enhanced at a time when transmission was blocked. Furtrethonium and its 5-methyl derivative have ganglionic actions identical to those of McN-A-343. It was concluded that these compounds stimulate two distinctive types of ganglionic receptors and cause a blockade of transmission by a mechanism different from that of C6. © 1967 by The Williams & Wilkins Company