Abstract
The pharmacological profiles of the 5-hydroxytryptamine (5-HT) receptors on Helix central neurones, Helix heart muscle and Helix pharyngeal retractor muscle (PRM) have been investigated. 5-Carboxyamidotryptamine proved a potent agonist at all sites, producing responses which were very similar to those of 5-HT. In general tryptamine analogues were active while non-tryptamine compounds possessed little or no 5-HT-like activity. A range of 5-HT antagonists were also tested against the excitatory responses of Helix neurones to 5-HT and acetylcholine. Cinanserin, tryptamine and ketanserin were selective antagonists against 5-HT compared to acetylcholine while cyanopindolol, bopindolol and pindolol showed no selectivity to 5-HT. The 5-HT agonist, MK 212, selectively blocked 5-HT in preference to acetylcholine excitation and dopamine inhibition while RU 24969 and RU 28253 showed blocking selectivity towards dopamine compared with 5-HT. It is concluded that the 5-HT receptors studied here cannot easily be identified in terms of the vertebrate classification into 5-HT-1,2 and 3 subtypes based on agonist and antagonist profiles.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
Boyd, P.J., Gardner, C.R. & Walker, R.J. (1985) ‘Actions of some 5-hydroxytryptamine analogues on the isolated heart of the snail, Helix aspersa’, Comp. Biochem. Physiol. 81C, 233–239.
Drummond, A.H., Bucher, F. & Levitan, I.B. (1980) ‘d-[3H]-Lysergic acid diethylamide binding to serotonin receptors in the molluscan nervous system’, J. Biol. Chem., 255, 6679–6686.
Fozard, J.R. (1987) 5-HT: ‘Enigma Variations’. Trends Pharmacol. Sci., 8, 501–506.
Gerschenfeld, H.M. & Paupardin-Tritsch, D. (1974) 1 Ionic mechanisms and receptor properties underlying the responses of molluscan neuronal membranes1, J. Physiol. ( Lond. ), 243, 427–456.
Greenberg, M.J. (1960) ‘Structure-activity relationship of tryptamine analogues on the heart of Venus mercenaria’, Br. J. Pharmacol. 15, 375–388.
Kerkut, G.A. & Leake, L.D. (1966) ‘The effects of drugs on the snail pharyngeal retractor muscle’, Comp. Biochem. Physiol, 17, 623–633.
Leake, L.D. & Walker, R.J. (1980) ‘Invertebrate Neuropharmacology’, Blackie, Glasgow, U.K., pp 1–385.
Maddrell, S.H.P., Pilcher, D.E.M. & Gardiner, B.O.C. (1971) ‘Pharmacology of the Malpighian tubules of Rhodnius and Carausisus: The structure-activity relationship of tryptamine analogues and the role of cAMP’, J. exp. Biol. 54, 779-
Sunderland, A.J., Leake, L.D. & Walker, R.J. (1982) ‘Structure- studies of the amine receptor on the Retzius cells of the leeches, Hirudo medicinalis and Haemopis sanquisuqa’. Comp. Biochem. physiol. 73C, 347–352.
Walker, R.J. (1985) ‘The Pharmacology of Serotonin Receptors in Invertebrates’, in, A.R. Green (ed.), Neuropharmacology of Serotonin, Oxford Univ. Press, Oxford, U.K., pp 366–408.
Walker, R.J. (1986) ‘Transmitters and Modulators in Molluscs’, in, A.O.D. Willows (ed.), The Mollusca: vol. 9, Neurobiology and Behaviour, part 2, Academic Press, Orlando, U.S.A., pp 279–485.
Wright, N.J.D. & Walker, R.J. (1984) ‘The possible site of action of 5-hydroxytryptamine, 6-hydroxytryptamine, tryptamine and dopamine on identified neurones in the central nervous system of the snail, Helix aspersa’. Comp. Biochem. Physiol. 78C, 217–225.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1990 Kluwer Academic Publishers
About this chapter
Cite this chapter
Walker, R.J., Vehovszky, A. (1990). 5-Hydroxytryptamine (5-HT) Receptor Subtypes in Invertebrates. In: Paoletti, R., Vanhoutte, P.M., Brunello, N., Maggi, F.M. (eds) Serotonin. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-1912-9_36
Download citation
DOI: https://doi.org/10.1007/978-94-009-1912-9_36
Publisher Name: Springer, Dordrecht
Print ISBN: 978-94-010-7353-0
Online ISBN: 978-94-009-1912-9
eBook Packages: Springer Book Archive