| Angiotensin II AT2 receptor stimulation extends the upper limit of cerebral blood flow autoregulation: agonist effects of CGP 42112 and PD 123319. | |
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MedLine Citation:
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PMID: 8263056 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The effects of the angiotensin II AT2 receptor ligands CGP 42112 and PD 123319, the AT1 antagonist losartan, and the nonselective angiotensin II antagonist Sar1,Ile8-angiotensin II on the upper limit of CBF autoregulation were studied in pentobarbital-anesthetized rats. Blood pressure was increased by intravenous phenylephrine infusion, while CBF was measured continuously from the parietal cortex by laser-Doppler flowmetry. Intravenous infusions of CGP 42112 (0.1 and 1 mg kg-1 min-1) and PD 123319 (0.36 and 1 mg kg-1 min-1) shifted the upper limit of CBF autoregulation toward higher blood pressures without affecting baseline CBF. Sar1,Ile8-angiotensin II (4 micrograms kg-1 min-1) had no effect on baseline CBF or CBF autoregulation but antagonized the effect of CGP 42112 and PD 123319. Losartan (10 mg/kg i.v. bolus) reduced baseline blood pressure and CBF and shifted the autoregulation curve toward higher blood pressures. Sar1,Ile8-angiotensin II blocked the effect of losartan on baseline CBF but not on CBF autoregulation. These results suggest that both CGP 42112 and PD 123319 exert their effects on CBF autoregulation through stimulation of angiotensin II AT2 receptors. The mechanism by which losartan affects CBF remains unclear. |
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Authors:
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L Näveri; C Strömberg; J M Saavedra |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism Volume: 14 ISSN: 0271-678X ISO Abbreviation: J. Cereb. Blood Flow Metab. Publication Date: 1994 Jan |
Date Detail:
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Created Date: 1994-01-25 Completed Date: 1994-01-25 Revised Date: 2003-11-14 |
Medline Journal Info:
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Nlm Unique ID: 8112566 Medline TA: J Cereb Blood Flow Metab Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 38-44 Citation Subset: IM |
Affiliation:
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Section on Pharmacology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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1-Sarcosine-8-Isoleucine Angiotensin II
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pharmacology Animals Biphenyl Compounds / pharmacology Blood Pressure / drug effects Cerebrovascular Circulation / drug effects, physiology* Homeostasis* / drug effects Imidazoles / antagonists & inhibitors, pharmacology* Injections, Intravenous Losartan Male Oligopeptides / antagonists & inhibitors, pharmacology* Phenylephrine / pharmacology Pyridines / antagonists & inhibitors, pharmacology* Rats Rats, Sprague-Dawley Receptors, Angiotensin / antagonists & inhibitors, drug effects*, metabolism* Tetrazoles / pharmacology |
| Chemical | |
Reg. No./Substance:
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0/Biphenyl Compounds; 0/Imidazoles; 0/Oligopeptides; 0/Pyridines; 0/Receptors, Angiotensin; 0/Tetrazoles; 114798-26-4/Losartan; 127060-75-7/CGP 42112A; 130663-39-7/PD 123319; 59-42-7/Phenylephrine; 9088-01-1/1-Sarcosine-8-Isoleucine Angiotensin II |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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