Abstract
1. In cortical slices from rat brain incubated in a medium containing the irreversible cholinesterase inhibitor, soman (0·005 mM) and a high concentration of KCl (25 mM), atropine exerts a stimulating action on the release of acetylcholine (ACh).
2. Two possible explanations for this action were examined. Atropine might expel ACh from the nerve endings by occupying its storage sites or it might prevent an inhibitory action of the released ACh on its further release by occupying muscarinic receptors at the presynaptic endings; its action would then be a kind of `disinhibition.'
3. The stimulating action of atropine on ACh release persisted during prolonged incubation (up to 3·5 h) provided choline was added to the medium. This finding would be difficult to explain if atropine acted by expelling ACh from its storage sites.
4. The stimulating action of atropine on ACh release was inhibited by oxotremorine and by methacholine, added to the medium in high concentrations. This finding is readily explained if atropine acts by `disinhibition.'
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bertels-Meeuws M. M., Polak R. L. Influence of antimuscarinic substances on in vitro synthesis of acetylcholine by rat cerebral cortex. Br J Pharmacol Chemother. 1968 Jun;33(2):368–380. doi: 10.1111/j.1476-5381.1968.tb00997.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- ELLIOTT K. A. C., SWANK R. L., HENDERSON N. Effects of anesthetics and convulsants on acetylcholine content of brain. Am J Physiol. 1950 Aug 1;162(2):469–474. doi: 10.1152/ajplegacy.1950.162.2.469. [DOI] [PubMed] [Google Scholar]
- Molenaar P. C., Polak R. L. Stimulation by atropine of acetylcholine release and synthesis in cortical slices from rat brain. Br J Pharmacol. 1970 Nov;40(3):406–417. doi: 10.1111/j.1476-5381.1970.tb10622.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Polak R. L., Meeuws M. M. The influence of atropine on the release and uptake of acetylcholine by the isolated cerebral cortex of the rat. Biochem Pharmacol. 1966 Jul;15(7):989–992. doi: 10.1016/0006-2952(66)90176-6. [DOI] [PubMed] [Google Scholar]
- Polak R. L. The influence of drugs on the uptake of acetylcholine by slices of rat cerebral cortex. Br J Pharmacol. 1969 May;36(1):144–152. doi: 10.1111/j.1476-5381.1969.tb08311.x. [DOI] [PMC free article] [PubMed] [Google Scholar]