Abstract
1. Acetylcholine (ACh) release from the cerebral cortex of freely moving guinea-pigs, implanted with epidural cups, was studied. 2. A single dose of chlorimipramine (Cl-Imip, 10 mg kg-1, s.c.), reduced the cortical ACh release both in normal and in chronically (10 mg kg-1 daily, s.c., for 14 days) Cl-Imip-treated guinea-pigs; the 5-HT3 antagonist MDL 72222 (1 mg kg-1, s.c.) antagonized this effect. 3. A single dose of Cl-Imip significantly reduced the effect of the 5-HT1A agonist 8-hydroxy-2-(di-n-propylaminotetralin) (8-OH-DPAT, 0.1 mg kg-1, s.c.), which nearly doubled the cortical ACh release in control animals. MDL 72222 restored to normal the response to 8-OH-DPAT reduced by the anti-depressant. 4. A single dose of Cl-Imip did not change the inhibitory, MDL 72222-sensitive, effect induced by the 5-HT3 agonist 2-methyl-5-hydroxytryptamine (2-methyl-5-HT, 500 micrograms, i.c.v.). 5. In chronically Cl-Imip-treated guinea-pigs, the facilitatory effect of 8-OH-DPAT was no longer present, while the inhibitory, MDL 72222-sensitive, effect of 2-methyl-5-HT was maintained. 6. These results indicate that the 5-HT1A receptor-mediated increase in ACh release is reduced by prolonged Cl-Imip treatment, while the 5-HT3 receptor-mediated inhibition of ACh release is unaffected. The relevance of these findings to the antidepressant mechanism of Cl-Imip is discussed.
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- Barnes J. M., Barnes N. M., Costall B., Naylor R. J., Tyers M. B. 5-HT3 receptors mediate inhibition of acetylcholine release in cortical tissue. Nature. 1989 Apr 27;338(6218):762–763. doi: 10.1038/338762a0. [DOI] [PubMed] [Google Scholar]
- Beani L., Bianchi C., Giacomelli A., Tamberi F. Noradrenaline inhibition of acetylcholine release from guinea-pig brain. Eur J Pharmacol. 1978 Mar 15;48(2):179–193. doi: 10.1016/0014-2999(78)90327-8. [DOI] [PubMed] [Google Scholar]
- Bianchi C., Siniscalchi A., Beani L. 5-HT1A agonists increase and 5-HT3 agonists decrease acetylcholine efflux from the cerebral cortex of freely-moving guinea-pigs. Br J Pharmacol. 1990 Oct;101(2):448–452. doi: 10.1111/j.1476-5381.1990.tb12728.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bianchi C., Siniscalchi A., Beani L. Effect of 5-hydroxytryptamine on [3H]-acetylcholine release from guinea-pig striatal slices. Br J Pharmacol. 1989 May;97(1):213–221. doi: 10.1111/j.1476-5381.1989.tb11944.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bianchi C., Siniscalchi A., Beani L. The influence of 5-hydroxytryptamine on the release of acetylcholine from guinea-pig brain ex vivo and in vitro. Neuropharmacology. 1986 Sep;25(9):1043–1049. doi: 10.1016/0028-3908(86)90200-5. [DOI] [PubMed] [Google Scholar]
- Blier P., Chaput Y., de Montigny C. Long-term 5-HT reuptake blockade, but not monoamine oxidase inhibition, decreases the function of terminal 5-HT autoreceptors: an electrophysiological study in the rat brain. Naunyn Schmiedebergs Arch Pharmacol. 1988 Mar;337(3):246–254. doi: 10.1007/BF00168834. [DOI] [PubMed] [Google Scholar]
- Bradley P. B., Engel G., Feniuk W., Fozard J. R., Humphrey P. P., Middlemiss D. N., Mylecharane E. J., Richardson B. P., Saxena P. R. Proposals for the classification and nomenclature of functional receptors for 5-hydroxytryptamine. Neuropharmacology. 1986 Jun;25(6):563–576. doi: 10.1016/0028-3908(86)90207-8. [DOI] [PubMed] [Google Scholar]
- Goodwin G. M., De Souza R. J., Green A. R. Presynaptic serotonin receptor-mediated response in mice attenuated by antidepressant drugs and electroconvulsive shock. Nature. 1985 Oct 10;317(6037):531–533. doi: 10.1038/317531a0. [DOI] [PubMed] [Google Scholar]
- Peroutka S. J., Snyder S. H. Long-term antidepressant treatment decreases spiroperidol-labeled serotonin receptor binding. Science. 1980 Oct 3;210(4465):88–90. doi: 10.1126/science.6251550. [DOI] [PubMed] [Google Scholar]
- Rudorfer M. V., Potter W. Z. Antidepressants. A comparative review of the clinical pharmacology and therapeutic use of the 'newer' versus the 'older' drugs. Drugs. 1989 May;37(5):713–738. doi: 10.2165/00003495-198937050-00006. [DOI] [PubMed] [Google Scholar]
- Siniscalchi A., Beani L., Bianchi C. Different effects of 8-OH-DPAT, a 5-HT1A receptor agonist, on cortical acetylcholine release, electrocortigram and body temperature in guinea pigs and rats. Eur J Pharmacol. 1990 Jan 10;175(2):219–223. doi: 10.1016/0014-2999(90)90235-x. [DOI] [PubMed] [Google Scholar]
- Siniscalchi A., Beani L., Bianchi C. Influence of chronic chlorimipramine treatment on the serotonergic modulation of acetylcholine release from guinea pig caudate nucleus slices. Neuropharmacology. 1990 Nov;29(11):1091–1093. doi: 10.1016/0028-3908(90)90118-b. [DOI] [PubMed] [Google Scholar]
- Wozniak K. M., Aulakh C. S., Hill J. L., Murphy D. L. Differential effect of clomipramine treatment on m-chlorophenylpiperazine-induced increases in plasma prolactin and corticosterone in rats. Pharmacol Biochem Behav. 1989 May;33(1):265–267. doi: 10.1016/0091-3057(89)90461-9. [DOI] [PubMed] [Google Scholar]