| Intermittent hypoxia increases arterial blood pressure in humans through a Renin-Angiotensin system-dependent mechanism. | |
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MedLine Citation:
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PMID: 20625082 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Intermittent hypoxia (IH) is believed to contribute to the pathogenesis of hypertension in obstructive sleep apnea through mechanisms that include activation of the renin-angiotensin system. The objective of this study was to assess the role of the type I angiotensin II receptor in mediating an increase in arterial pressure associated with a single 6-hour IH exposure. Using a double-blind, placebo-controlled, randomized, crossover study design, we exposed 9 healthy male subjects to sham IH, IH with placebo medication, and IH with the type I angiotensin II receptor antagonist losartan. We measured blood pressure, cerebral blood flow, and ventilation at baseline and after exposure to 6 hours of IH. An acute isocapnic hypoxia experimental protocol was conducted immediately before and after exposure to IH. IH with placebo increased resting mean arterial pressure by 7.9+/-1.6 mm Hg, but mean arterial pressure did not increase with sham IH (1.9+/-1.5 mm Hg) or with losartan IH (-0.2+/-2.4 mm Hg; P<0.05). Exposure to IH prevented the diurnal decrease in the cerebral blood flow response to hypoxia, independently of the renin-angiotensin system. Finally, in contrast to other models of IH, the acute hypoxic ventilatory response did not change throughout the protocol. IH increases arterial blood pressure through activation of the type I angiotensin II receptor, without a demonstrable impact on the cerebrovascular or ventilatory response to acute hypoxia. |
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Authors:
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Glen E Foster; Patrick J Hanly; Sofia B Ahmed; Andrew E Beaudin; Vincent Pialoux; Marc J Poulin |
Publication Detail:
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Type: Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't Date: 2010-07-12 |
Journal Detail:
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Title: Hypertension Volume: 56 ISSN: 1524-4563 ISO Abbreviation: Hypertension Publication Date: 2010 Sep |
Date Detail:
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Created Date: 2010-08-19 Completed Date: 2010-09-13 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 7906255 Medline TA: Hypertension Country: United States |
Other Details:
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Languages: eng Pagination: 369-77 Citation Subset: IM |
Affiliation:
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Department of Physiology and Pharmacology and Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adult Analysis of Variance Angiotensin II Type 1 Receptor Blockers / pharmacology Anoxia / physiopathology* Blood Pressure / drug effects, physiology* Cerebrovascular Circulation / drug effects, physiology Cross-Over Studies Double-Blind Method Humans Losartan / pharmacology Male Receptor, Angiotensin, Type 1 / physiology Renin-Angiotensin System / drug effects, physiology* |
| Grant Support | |
ID/Acronym/Agency:
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//Canadian Institutes of Health Research |
| Chemical | |
Reg. No./Substance:
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0/Angiotensin II Type 1 Receptor Blockers; 0/Receptor, Angiotensin, Type 1; 114798-26-4/Losartan |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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