| Reduction of ventricular fibrillation threshold by histamine: resolution into separate H1- and H2-mediated components. | |
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MedLine Citation:
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PMID: 6128405 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The effects of histamine and the selective agonists impromidine (H2-agonist) and 2-(2-thiazolyl ethylamine)(H1-agonist) on ventricular fibrillation threshold were tested in the isolated guinea-pig heart. All three compounds produced reversible concentration-dependent decreases in ventricular fibrillation threshold. Ventricular fibrillation threshold reduction was not secondary to the positive chronotropic effect of the three compounds. Computer analysis of the data using appropriate theoretical models suggests that the net effect of histamine on ventricular fibrillation threshold is the resultant of two components: H1 and H2. Pyrilamine inhibited the H1-mediated effects of histamine on ventricular fibrillation threshold with a Kb value of 0.449 nM. H1- and H2-receptors mediating ventricular fibrillation threshold reduction differ in their relative sensitivity to histamine (H1 greater than H2; EC50 for histamine, 53.9 nM at H1- and 311 nM at H2-receptors) and in the maximum response which they are capable of producing (H1 congruent to 1/2 that of H2). The finding that extremely low concentrations of histamine (less than 1 pg/ml) can effectively reduce ventricular fibrillation threshold reinforces the concept that histamine is highly arrhythmogenic. |
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Authors:
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J P Trzeciakowski; R Levi |
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Publication Detail:
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Type: In Vitro; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: The Journal of pharmacology and experimental therapeutics Volume: 223 ISSN: 0022-3565 ISO Abbreviation: J. Pharmacol. Exp. Ther. Publication Date: 1982 Dec |
Date Detail:
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Created Date: 1983-01-27 Completed Date: 1983-01-27 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 0376362 Medline TA: J Pharmacol Exp Ther Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 774-83 Citation Subset: IM |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Guinea Pigs Heart Rate / drug effects Histamine / pharmacology* Histamine H1 Antagonists / pharmacology Histamine H2 Antagonists / pharmacology Male Models, Cardiovascular Receptors, Histamine / physiology* Receptors, Histamine H1 / drug effects, physiology* Receptors, Histamine H2 / drug effects, physiology* Ventricular Fibrillation / physiopathology* |
| Grant Support | |
ID/Acronym/Agency:
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20091//PHS HHS |
| Chemical | |
Reg. No./Substance:
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0/Histamine H1 Antagonists; 0/Histamine H2 Antagonists; 0/Receptors, Histamine; 0/Receptors, Histamine H1; 0/Receptors, Histamine H2; 51-45-6/Histamine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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