Abstract
1. Surplus acetylcholine (ACh) is the extra ACh that accumulates in cholinergic nerve endings when they are exposed to an anticholinesterase agent. The synthesis and turnover of this ACh was examined in the cat's superior cervical ganglion.
2. Surplus ACh did not accumulate in chronically decentralized ganglia perfused with eserine-choline-Locke solution, and this shows that it is stored in presynaptic nerve terminals.
3. Surplus ACh accumulated more rapidly in ganglia perfused with eserine than in ganglia perfused with neostigmine or with ambenonium; accumulation was delayed by 45-60 min when a quaternary anticholinesterase was used. However, the release of ACh upon preganglionic nerve stimulation was the same during perfusion with eserine, neostigmine or ambenonium. It is concluded that intracellular acetylcholinesterase normally destroys surplus ACh, whereas extracellular enzyme destroys released ACh.
4. When ganglia were perfused with [3H]choline and eserine, the surplus ACh that accumulated was labelled but its specific radioactivity was only 38% of that of the choline added to the perfusion fluid.
5. Surplus ACh was not released by nerve stimulation and was not mobilized for release during, or after, prolonged nerve stimulation. It is concluded that ACh released by nerve impulses is replaced by synthesis at the site of ACh storage and not by movement of ACh from the surplus pool.
6. The accumulation of surplus ACh no more than doubled the total ACh content of ganglia, but turnover of ACh continued when the total amount was constant. Surplus ACh may contribute to spontaneous ACh output from eserinized preparations.
7. When ganglia were perfused with a medium containing high K+ (56 mM), surplus ACh was released.
Full text
PDF















Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BANISTER J., SCRASE M. Acetylcholine synthesis in normal and denervated sympathetic ganglia of the cat. J Physiol. 1950 Oct 16;111(3-4):437–444. doi: 10.1113/jphysiol.1950.sp004494. [DOI] [PMC free article] [PubMed] [Google Scholar]
- BIRKS R. I., MACINTOSH F. C., SASTRY P. B. Pharmacological inhibition of acetylcholine synthesis. Nature. 1956 Nov 24;178(4543):1181–1181. doi: 10.1038/1781181a0. [DOI] [PubMed] [Google Scholar]
- BIRKS R. I. THE ROLE OF SODIUM IONS IN THE METABOLISM OF ACETYLCHOLINE. Can J Biochem Physiol. 1963 Dec;41:2573–2597. [PubMed] [Google Scholar]
- BLIGH J. The level of free choline in plasma. J Physiol. 1952 Jun;117(2):234–240. doi: 10.1113/jphysiol.1952.sp004743. [DOI] [PMC free article] [PubMed] [Google Scholar]
- BURGEN A. S. V., CHIPMAN L. M. The location of cholinesterase in the central nervous system. Q J Exp Physiol Cogn Med Sci. 1952;37(2):61–74. doi: 10.1113/expphysiol.1952.sp000983. [DOI] [PubMed] [Google Scholar]
- Brown G. L., Feldberg W. The acetyloholine metabolism of a sympathetic ganglion. J Physiol. 1936 Dec 11;88(3):265–283. doi: 10.1113/jphysiol.1936.sp003439. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brown G. L., Feldberg W. The action of potassium on the superior cervical ganglion of the cat. J Physiol. 1936 Mar 9;86(3):290–305. doi: 10.1113/jphysiol.1936.sp003364. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Collier B., Lang C. The metabolism of choline by a sympathetic ganglion. Can J Physiol Pharmacol. 1969 Feb;47(2):119–126. doi: 10.1139/y69-022. [DOI] [PubMed] [Google Scholar]
- Dudley H. W. Observations on acetylcholine. Biochem J. 1929;23(5):1064–1074. doi: 10.1042/bj0231064. [DOI] [PMC free article] [PubMed] [Google Scholar]
- EMMELIN N., MACINTOSH F. C. The release of acetylcholine from perfused sympathetic ganglia and skeletal muscles. J Physiol. 1956 Feb 28;131(2):477–496. doi: 10.1113/jphysiol.1956.sp005477. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Feldberg W., Gaddum J. H. The chemical transmitter at synapses in a sympathetic ganglion. J Physiol. 1934 Jun 9;81(3):305–319. doi: 10.1113/jphysiol.1934.sp003137. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Feldberg W. Synthesis of acetylcholine in sympathetic ganglia and cholinergic nerves. J Physiol. 1943 Mar 25;101(4):432–445. doi: 10.1113/jphysiol.1943.sp003997. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Friesen A. J., Ling G. M., Nagai M. Choline and phospholipid-choline in a sympathetic ganglion and their relationship to acetylcholine synthesis. Nature. 1967 May 13;214(5089):722–724. doi: 10.1038/214722a0. [DOI] [PubMed] [Google Scholar]
- GARDINER J. E. The inhibition of acetylcholine synthesis in brain by a hemicholinium. Biochem J. 1961 Nov;81:297–303. doi: 10.1042/bj0810297. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KOELLE W. A., KOELLE G. B. The localization of external or functional acetylcholinesterase at the synapses of autonomic ganglia. J Pharmacol Exp Ther. 1959 May;126(1):1–8. [PubMed] [Google Scholar]
- Kahlson G., Macintosh F. C. Acetylcholine synthesis in a sympathetic ganglion. J Physiol. 1939 Aug 14;96(3):277–292. doi: 10.1113/jphysiol.1939.sp003776. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MATTHEWS E. K. THE EFFECTS OF CHOLINE AND OTHER FACTORS ON THE RELEASE OF ACETYLCHOLINE FROM THE STIMULATED PERFUSED SUPERIOR CERVICAL GANGLION OF THE CAT. Br J Pharmacol Chemother. 1963 Oct;21:244–249. doi: 10.1111/j.1476-5381.1963.tb01523.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marchbanks R. M. The uptake of [14C] choline into synaptosomes in vitro. Biochem J. 1968 Dec;110(3):533–541. doi: 10.1042/bj1100533. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mitchell J. F., Silver A. The spontaneous release of acetylcholine from the denervated hemidiaphragm of the rat. J Physiol. 1963 Jan;165(1):117–129. doi: 10.1113/jphysiol.1963.sp007046. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Potter L. T. Synthesis, storage and release of [14C]acetylcholine in isolated rat diaphragm muscles. J Physiol. 1970 Jan;206(1):145–166. doi: 10.1113/jphysiol.1970.sp009003. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Quastel J. H., Tennenbaum M., Wheatley A. H. Choline ester formation in, and choline esterase activities of, tissues in vitro. Biochem J. 1936 Sep;30(9):1668–1681. doi: 10.1042/bj0301668. [DOI] [PMC free article] [PubMed] [Google Scholar]