| Analysis of adrenoceptor blockade and hypotension elicited by urapidil and prazosin in conscious rat. | |
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MedLine Citation:
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PMID: 2871176 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The adrenoceptor blocking properties and hypotensive effects of the alpha-1 blocking agents urapidil and prazosin were compared in conscious instrumented rats. Both urapidil and prazosin in i.v. doses of 3 and 6 mg/kg and 0.125 and 0.25 mg/kg, respectively, blocked the pressor response to the alpha-1 adrenoceptor agonist phenylephrine. The hypotensive effects of urapidil and prazosin in these doses were equivalent. Mechanisms of the blood pressure compensation to urapidil-induced hypotension were examined with the arginine vasopressin (AVP) antagonist, d(CH2)5Tyr(Me)AVP, and the angiotensin converting enzyme inhibitor, MK-422. Urapidil alone (6 mg/kg i.v.) and after the AVP antagonist caused a similar degree of hypotension (22 and 15% decrease, respectively, in mean blood pressure). When the alpha-1 antagonist was administered after converting enzyme inhibition, it caused a significantly greater decrease in blood pressure (37%) than in the previous two groups, but not different from that obtained after combined AVP antagonism and converting enzyme inhibition (30% decrease). These results indicate that the renin-angiotensin system compensates for the hypotensive effect due to alpha-1 adrenoceptor blockade, whereas AVP, even assuming that the circulating level was increased by urapidil, was without effect on blood pressure. |
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Authors:
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J Goering; B G Zimmerman |
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Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: The Journal of pharmacology and experimental therapeutics Volume: 237 ISSN: 0022-3565 ISO Abbreviation: J. Pharmacol. Exp. Ther. Publication Date: 1986 May |
Date Detail:
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Created Date: 1986-06-23 Completed Date: 1986-06-23 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: 553-7 Citation Subset: IM |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adrenergic alpha-Antagonists
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pharmacology* Analysis of Variance Animals Antihypertensive Agents / pharmacology* Arginine Vasopressin / physiology Blood Pressure / drug effects* Enalapril / analogs & derivatives, pharmacology Enalaprilat Male Phenylephrine / pharmacology Piperazines / pharmacology* Prazosin / pharmacology* Rats Rats, Inbred Strains Renin-Angiotensin System |
| Grant Support | |
ID/Acronym/Agency:
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HL17871/HL/NHLBI NIH HHS; HL30758/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Adrenergic alpha-Antagonists; 0/Antihypertensive Agents; 0/Piperazines; 113-79-1/Arginine Vasopressin; 19216-56-9/Prazosin; 34661-75-1/urapidil; 59-42-7/Phenylephrine; 75847-73-3/Enalapril; 84680-54-6/Enalaprilat |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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