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Serotonin and acetylcholine: further analysis of praziquantel-induced contraction of magnesium-paralysed Schistosoma mansoni

Published online by Cambridge University Press:  06 April 2009

K. L. Blair
Affiliation:
Department of Zoology and Neuroscience Program, Michigan State University, East Lansing, MI 48824-1115, USA
J. L. Bennett
Affiliation:
Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824-1115, USA
R. A. Pax
Affiliation:
Department of Zoology and Neuroscience Program, Michigan State University, East Lansing, MI 48824-1115, USA

Summary

The nature of stimulus-induced flaccid paralysis produced in Mg2+-paralysed Schistosoma mansoni was investigated. Serotonin induced a dose-dependent, heterologous flaccid paralysis with an IC50 of 600 nm. This flaccid paralysis was a function of the extracellular Mg2+:Ca2+ ratio and was reversible. Tonic contractions produced by phorbol-12,13- dibutyrate or 60 mM K+ were reversed by the application of serotonin and flaccid paralysis was induced. These actions of serotonin were mimicked by forskolin and synergized by IBMX but the potassium channel blocker, 3,4-DAP, did not produce flaccid paralysis. When Mg2+-paralysed parasites were stimulated with 3,4-DAP, IBMX produced a dose- dependent flaccid paralysis with an IC50 of 11 μm. Membrane permeable analogues of cAMP and cGMP did not synergize with IBMX. Cholinergic agonists, but not other inhibitory substances, prevented the serotonin- and forskolin-induced and the IBMX-synergized flaccid paralysis but not that produced by praziquantel. The possible interactions of these agents with the muscle are discussed.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1993

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References

REFERENCES

Blair, K. L., Bennett, J. L. & Pax, R. L. (1992). Praziquantel: physiological evidence for its site(s) of action in magnesium-paralysed Schistosoma mansoni. Parasitology 104, 5966.Google Scholar
Estey, S. J. & Mansour, T. E. (1987). Nature of serotonin-activated adenylate cyclase during development of Schistosoma mansoni. Molecular and Biochemical Parasitology 26, 4760.Google Scholar
Estey, S. J. & Mansour, T. E. (1988). GTP binding regulatory proteins of adenylate cyclase in Schistosoma mansoni at different stages of development. Molecular and Biochemical Parasitology 30, 6776.CrossRefGoogle ScholarPubMed
Fetterer, R. H., Pax, R. A. & Bennett, J. L. (1977). Schistosoma mansoni: direct method of simultaneous recordings of electrical and motor activity. Experimental Parasitology 43, 286–94.CrossRefGoogle ScholarPubMed
Fetterer, R. H., Pax, R. A., Thompson, D. P., Bricker, C. & Bennett, J. L. (1980). Praziquantel: mode of its antischistosomal action. In The Host Invader Interplay (ed. Van den Bossche, H.), pp. 695–8. Amsterdam: Elsevier, North Holland Biomedical Press.Google Scholar
Formenti, A. & Sansone, V. (1991). Inhibitory action of acetylcholine, baclofen and GTP-γ-S on calcium channels in adult rat sensory neurons. Neuroscience Letters 131, 267–72.Google Scholar
Galione, A. (1992). Ca2+-induced Ca2+ release and its modulation by cyclic ADP-ribose. Trends in Pharmacological Science 13, 304–6.Google Scholar
Lotshaw, D. P. & Levitan, I. B. (1988). Reciprocal modulation of calcium current by serotonin and dopamine in the identified Aplysia neuron R15. Brain Research 439, 6476.Google Scholar
Pax, R. A., Bennett, J. L. & Fetterer, R. (1978). A benzodiazepine derivative and praziquantel: effects on musculature of Schistosoma mansoni and Schistosoma japonicum. Naunyn-Schmiedebergs Archiv für experimentelle Pathologie und Pharmacologie 304, 309–15.CrossRefGoogle ScholarPubMed
Pax, R. A., Siefker, C. & Bennett, J. L. (1984). Schistosoma mansoni: differences in acetylcholine, dopamine, and serotonin control of circular and longitudinal parasite muscles. Experimental Parasitology 58, 314–24.CrossRefGoogle ScholarPubMed
Pax, R. A., Thompson, D. P. & Bennett, J. L. (1983). Action of praziquantel and the benzodiazepines on adult male Schistosoma mansoni. In Mechanism of Drug Action (ed. Singer, T., Mansour, T. & Ondarza, R.), pp. 187–96. Orlando: Academic Press.Google Scholar
Semeyn, D. R., Pax, R. A. & Bennett, J. L. (1982). Surface electrical activity from Schistosoma mansoni: a sensitive measure of drug action. Journal of Parasitology 68, 353–62.Google Scholar
Wiest, P. M., Li, Y., Burnham, D. C., Olds, G. R. & Bowden, W. D. (1992). Schistosoma mansoni: characterization of phosphoinositide response. Experimental Parasitology 74, 3845.Google Scholar