| Do centrally-acting antihypertensive drugs act at non-adrenergic as well as alpha-2 adrenoceptor sites? | |
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MedLine Citation:
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PMID: 1327589 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Rabbits were treated with guanabenz, clonidine and rilmenidine for 6 days via osmotic minipumps. Blood pressure, heart rate and responses to intracisternal clonidine were measured after 1 and 6 days treatment. Radioligand binding to forebrain and hindbrain membranes after 6 days treatment was examined using [3H]yohimbine to measure the number of adrenergic binding sites and [3H]clonidine and [3H]idazoxan to assess nonadrenergic imidazoline sites. No change in nonadrenergic imidazoline binding was observed but adrenergic binding was decreased in forebrain and hindbrain by guanabenz and in hindbrain by clonidine treatment. Resting heart rate was decreased after 1 day's treatment with partial recovery by day 6. At this time heart rate significantly reduced in the clonidine and rilmenidine treated groups but not the guanabenz group. No significant change in baseline blood pressure was observed in normotensive rabbits. Both depressor and bradycardia responses to intracisternal clonidine were attenuated after 1 day's dosing but only depressor responses were influenced after 6 days. Blood pressure and heart rate thus appeared to be regulated independently. It is possible that imidazoline receptors predominate in the central control of blood pressure while central alpha-2 adrenoceptors play a greater part in heart rate regulation. |
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Authors:
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C A Hamilton; M A Yakubu; C A Howie; J L Reid |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Clinical and experimental hypertension. Part A, Theory and practice Volume: 14 ISSN: 0730-0077 ISO Abbreviation: Clin Exp Hypertens A Publication Date: 1992 |
Date Detail:
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Created Date: 1992-11-04 Completed Date: 1992-11-04 Revised Date: 2008-02-12 |
Medline Journal Info:
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Nlm Unique ID: 8207790 Medline TA: Clin Exp Hypertens A Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 815-35 Citation Subset: IM |
Affiliation:
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University Department of Medicine and Therapeutics Western Infirmary, Glasgow. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Antihypertensive Agents / pharmacology* Binding Sites Blood Pressure / drug effects Brain / metabolism, physiology* Cisterna Magna Clonidine / pharmacology Guanabenz / pharmacology Heart Rate / drug effects Infusion Pumps Injections Male Osmosis Oxazoles / pharmacology Rabbits Radioligand Assay Receptors, Adrenergic, alpha / metabolism* Receptors, Cell Surface / metabolism* |
| Chemical | |
Reg. No./Substance:
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0/Antihypertensive Agents; 0/Oxazoles; 0/Receptors, Adrenergic, alpha; 0/Receptors, Cell Surface; 4205-90-7/Clonidine; 5051-62-7/Guanabenz; 54187-04-1/rilmenidine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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