Document Detail


Role of the renin-angiotensin system in hypertension during reduced uteroplacental perfusion pressure.
MedLine Citation:
PMID:  2665522     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Utero-placental ischemia is known to cause systemic hypertension in various species, but the mechanisms are unknown. These studies were designed to test the hypothesis that the increased systemic arterial pressure that occurs during reduced utero-placental perfusion pressure is mediated by the renin-angiotensin system, possibly due to release of renin or angiotensin from the ischemic gravid uterus. In trained, chronically instrumented pregnant dogs (gestational age 47 +/- 2 days, term = 60 days) maintained on a normal Na+ intake (approximately 80 meq/day), uterine perfusion pressure was reduced to 60 mmHg with an inflatable aortic occluder positioned distal to the renal arteries but proximal to the uterine arteries and was servo-controlled at this level for 1 h. Systemic arterial pressure rose by 14 +/- 2 mmHg, from 96 +/- 7 to 110 +/- 8 mmHg. Plasma renin activity and angiotensin II levels did not change significantly. On another day in the same animals, the activity of the renin-angiotensin system was fixed by infusing captopril and sufficient angiotensin II to restore arterial pressure to normal (2-5 ng.kg-1.min-1 iv). Reduction of uterine artery pressure to 60 mmHg caused systemic arterial pressure to increase by 10 +/- 2 mmHg with the renin-angiotensin system fixed, a response not different from that in the control experiments. These data suggest that the increase in systemic arterial pressure during reduced uteroplacental perfusion pressure is independent of the renin-angiotensin system.
Authors:
L L Woods; V L Brooks
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  257     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1989 Jul 
Date Detail:
Created Date:  1989-08-16     Completed Date:  1989-08-16     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  R204-9     Citation Subset:  IM    
Affiliation:
Division of Nephrology and Hypertension, Oregon Health Sciences University, Portland 97201.
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MeSH Terms
Descriptor/Qualifier:
Angiotensin II / blood,  pharmacology
Animals
Blood Pressure / drug effects
Dogs
Female
Hypertension / etiology*
Placenta / blood supply*
Pregnancy
Pregnancy Complications, Cardiovascular / etiology*
Regional Blood Flow
Renin / blood
Renin-Angiotensin System*
Uterus / blood supply*
Grant Support
ID/Acronym/Agency:
HD-24915/HD/NICHD NIH HHS; HL-39923/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
11128-99-7/Angiotensin II; EC 3.4.23.15/Renin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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