Abstract
1 The hyperactivity syndrome produced in rats by administration of tranylcypromine (20 mg/kg i.p.) followed 30 min later by L-tryptophan (50 mg/kg i.p.) is generally considered to be due to increased 5-hydroxytryptamine (5-HT) functional activity. It is inhibited by chlorpromazine (30 mg/kg i.p.) injected 60 min before the tranylcypromine. However, chlorpromazine injection for 4 days either at a dose of 30 mg/kg once daily or 5 mg/kg twice daily results in an enhanced hyperactivity response to tranylcypromine and L-tryptophan administration 24 h after the final dose of chlorpromazine. 2 One injection of chlorpromazine (30 mg/kg) did not produce enhancement 24 h later and the inhibition of the tranylcypromine/L-tryptophan hyperactivity observed after acute chlorpromazine injection was seen if the rats were given tranylcypromine and L-tryptophan 1 h after the fourth chlorpromazine (30 mg/kg) dose. 3 Chlorpromazine (30 mg/kg) once daily or 5 mg/kg twice daily for 4 days resulted in rats displaying enhanced behavioral responses to the suggested 5-HT agonist 5-methoxy N,N-dimethyltryptamine (2 mg/kg) on day 5. 4 Chlorpromazine (30 mg/kg) once daily for 4 days produces a slight increase in brain 5-hydroxytryptamine (5-HT) concentration on day 5, but no difference in the rate of brain 5-HT synthesis or the rate of 5-HT accumulation after tranylcypromine and L-tryptophan administration. 5. There is some evidence that chlorpromazine blocks 5-HT receptors. It has also been observed that several other neuroleptic drugs do not produce enhanced 5-HT responses after repeated administration. It is suggested therefore that the enhanced behavioural response to 5-HT receptor stimulation following repeated chlorpromazine administration may be because this drug blocks 5-HT receptors.
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Selected References
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- Bender D. A. The effects of chlorpromazine on serum tryptophan, brain tryptophan uptake and brain serotonin synthesis in the rat. Biochem Pharmacol. 1976 Aug 1;25(15):1743–1746. doi: 10.1016/0006-2952(76)90408-1. [DOI] [PubMed] [Google Scholar]
- Curzon G., Green A. R. Rapid method for the determination of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid in small regions of rat brain. Br J Pharmacol. 1970 Jul;39(3):653–655. doi: 10.1111/j.1476-5381.1970.tb10373.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Denckla W. D., Dewey H. K. The determination of tryptophan in plasma, liver, and urine. J Lab Clin Med. 1967 Jan;69(1):160–169. [PubMed] [Google Scholar]
- Dominic J. A., Moore K. E. Supersensitivity to the central stimulant actions of adrenergic drugs following discontinuation of a chronic diet of alpha-methyltyrosine. Psychopharmacologia. 1969;15(2):96–101. doi: 10.1007/BF00407041. [DOI] [PubMed] [Google Scholar]
- Gianutsos G., Drawbaugh R. B., Hynes M. D., Lal H. Behavioral evidence for dopaminergic supersensitivity after chronic haloperidol. Life Sci. 1974 Mar 1;14(5):887–898. doi: 10.1016/0024-3205(74)90078-2. [DOI] [PubMed] [Google Scholar]
- Grahame-Smith D. G. Studies in vivo on the relationship between brain tryptophan, brain 5-HT synthesis and hyperactivity in rats treated with a monoamine oxidase inhibitor and L-tryptophan. J Neurochem. 1971 Jun;18(6):1053–1066. doi: 10.1111/j.1471-4159.1971.tb12034.x. [DOI] [PubMed] [Google Scholar]
- Green A. R., Grahame-Smith D. G. Effects of drugs on the processes regulating the functional activity of brain 5-hydroxytryptamine. Nature. 1976 Apr 8;260(5551):487–491. doi: 10.1038/260487a0. [DOI] [PubMed] [Google Scholar]
- Green A. R., Grahame-Smith D. G. The role of brain dopamine in the hyperactivity syndrome produced by increased 5-hydroxytryptamine synthesis in rats. Neuropharmacology. 1974 Nov;13(10-11):949–959. doi: 10.1016/0028-3908(74)90086-0. [DOI] [PubMed] [Google Scholar]
- Heal D. J., Green A. R., Boullin D. J., Grahame-Smith D. G. Single and repeated administration of neuroleptic drugs to rats: effects on striatal dopamine-sensitive adenylate cyclase and locomotor activity produced by tranylcypromine and L-tryptophan or L-Dopa. Psychopharmacology (Berl) 1976 Sep 29;49(3):287–300. doi: 10.1007/BF00426832. [DOI] [PubMed] [Google Scholar]
- Klawans H. L., D'Amico D. J., Patel B. C. Behavioral supersensitivity to 5-hydroxytryptophan induced by chronic methysergide pretreatment. Psychopharmacologia. 1975 Nov 21;44(3):297–300. doi: 10.1007/BF00428910. [DOI] [PubMed] [Google Scholar]
- Moore K. E., Thornburg J. E. Drug-induced dopaminergic supersensitivity. Adv Neurol. 1975;9:93–104. [PubMed] [Google Scholar]
- Neff N. H., Tozer T. N. In vivo measurement of brain serotonin turnover. Adv Pharmacol. 1968;6(Pt A):97–109. doi: 10.1016/s1054-3589(08)61160-6. [DOI] [PubMed] [Google Scholar]
- Tarsy D., Baldessarini R. J. Pharmacologically induced behavioural supersensitivity to apomorphine. Nat New Biol. 1973 Oct 31;245(148):262–263. doi: 10.1038/newbio245262a0. [DOI] [PubMed] [Google Scholar]
- Trulson M. E., Eubanks E. E., Jacobs B. L. Behavioral evidence for supersensitivity following destruction of central serotonergic nerve terminals by 5,7-dihydroxytryptamine. J Pharmacol Exp Ther. 1976 Jul;198(1):23–32. [PubMed] [Google Scholar]
- von Hungen K., Roberts S., Hill D. F. Serotonin-sensitive adenylate cyclase activity of immature rat brain. Brain Res. 1975 Feb 7;84(2):257–267. doi: 10.1016/0006-8993(75)90980-4. [DOI] [PubMed] [Google Scholar]