| RFamide neuropeptide actions on the molluscan heart. | |
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MedLine Citation:
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PMID: 15270250 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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FMRFamide and the related tetrapeptide FLRFamide are highly excitatory in molluscan non-cardiac smooth muscle. They are also exceptionally excitatory in the atrium and internally perfused ventricle of Busycon canaliculatum. These two peptides, usually thought of as classic molluscan cardio-acceleratory agents are in fact simply two members of a large and ever growing superfamily, the RFamide family, whose phylogenetic distribution has been so elegantly mapped by Walker. Members of this family, often with extended peptide chains (e.g. penta, hepta and decapeptides), stretch in their known distribution from the cnidaria to the chordates. The effects of some of the members of this superfamily (FMRFamide. FLRFamide, YMRFamide, TNRNFLRFamide, SDPFLRFamide, LMS) were examined. The neuropeptides were found to be very potent at very low concentrations (10(-9) M) in the ventricle of both Buccinium and Busycon. Other neuropeptides (HFMRdFamide, SCPb, NLERFamide and pEGRFamide) were found to be without any effect. The Ca2+ dependency of these neuropeptides was also tested. The peptides appear to induce contraction of the ventricles by release of Ca2+ from internal pools. The neuropeptides appear to stimulate contraction in these cardiac muscles through a completely different pathway to Serotonin (the main excitatory neurotransmitter for the cardiac muscle). When the peptides were applied together with Serotonin an additive effect was observed clearly indicating the release of Ca2+ through different pathways. The nature of the RFamide receptor was also tested. It appears that the RFamide neuropeptides mobilize the 2nd messenger IP3 (Inositol trisphosphate), since the IP3 blocker Neomycin Sulphate inhibited the response of the neuropeptides. |
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Authors:
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A Moulis |
Publication Detail:
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Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Acta biologica Hungarica Volume: 55 ISSN: 0236-5383 ISO Abbreviation: Acta. Biol. Hung. Publication Date: 2004 |
Date Detail:
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Created Date: 2004-07-23 Completed Date: 2005-01-13 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 8404358 Medline TA: Acta Biol Hung Country: Hungary |
Other Details:
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Languages: eng Pagination: 335-41 Citation Subset: IM |
Affiliation:
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Department of Biological Sciences, Lancaster University, Lancaster LA1 4YT, UK. moulis@exchange.lancs.ac.uk |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Calcium / metabolism Dose-Response Relationship, Drug Electrophysiology FMRFamide / metabolism Inositol Phosphates / metabolism Mollusca Myocardium / metabolism* Neomycin / pharmacology Neuropeptides / chemistry*, metabolism* Neurotransmitter Agents Oligopeptides / metabolism Peptides / chemistry Protein Synthesis Inhibitors / pharmacology Seawater Species Specificity Time Factors |
| Chemical | |
Reg. No./Substance:
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0/Inositol Phosphates; 0/Neuropeptides; 0/Neurotransmitter Agents; 0/Oligopeptides; 0/Peptides; 0/Protein Synthesis Inhibitors; 1404-04-2/Neomycin; 34388-59-5/arginylphenylalaninamide; 64190-70-1/FMRFamide; 7440-70-2/Calcium; 80690-77-3/phenylalanyl-leucyl-arginyl phenylalaninamide |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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