Document Detail

Effect of ovariectomy on blood pressure and venous tone in female spontaneously hypertensive rats.
MedLine Citation:
PMID:  18636067     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Venous capacitance plays an important role in circulatory homeostasis. A number of reports have suggested an effect of estrogen on venous function. This study tested the hypothesis that ovariectomy would increase venous tone in the female spontaneously hypertensive rat (SHR) via autonomic mechanisms. METHODS: Five-week-old female SHR were subjected to sham operation (Sham) or ovariectomy (OVX). At 10 weeks of age, the rats were instrumented for the measurement of arterial and venous pressure. A balloon catheter was advanced into the right atrium. Mean circulatory filling pressure (MCFP), an index of venous tone, was calculated. Mean arterial pressure (MAP), heart rate (HR), and MCFP were recorded from conscious rats. Postsynaptic adrenergic responsiveness was assessed by constructing cumulative dose-response curves to norepinephrine (NE). RESULTS: MAP was not significantly affected by ovariectomy (Sham 127 +/- 6 mm Hg vs. OVX 130 +/- 3 mm Hg). HR also was not different between groups (Sham 409 +/- 11 bpm vs. OVX 399 +/- 12 bpm). Conversely, MCFP was significantly, but moderately, increased in OVX SHR (Sham 5.2 +/- 0.2 mm Hg vs. OVX 5.9 +/- 0.2 mm Hg). Ganglionic blockade produced marked decreases in MAP, HR, and MCFP in both groups; however, the responses were not different between groups. Infusion of NE caused dose-dependent increases in MAP and MCFP. There were no statistically significant differences in these responses between Sham and OVX SHR. CONCLUSION: Endogenous ovarian hormones effect a small reduction in MCFP. This effect does not appear to be mediated by adrenergic mechanisms.
Douglas S Martin; Rebecca Redetzke; Erin Vogel; Connie Mark; Kathleen M Eyster
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2008-07-17
Journal Detail:
Title:  American journal of hypertension     Volume:  21     ISSN:  0895-7061     ISO Abbreviation:  Am. J. Hypertens.     Publication Date:  2008 Sep 
Date Detail:
Created Date:  2008-08-26     Completed Date:  2009-01-07     Revised Date:  2009-02-24    
Medline Journal Info:
Nlm Unique ID:  8803676     Medline TA:  Am J Hypertens     Country:  United States    
Other Details:
Languages:  eng     Pagination:  983-8     Citation Subset:  IM    
Basic Biomedical Sciences, University of South Dakota Sanford School of Medicine, Vermillion, South Dakota, USA.
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MeSH Terms
Blood Pressure / physiology*
Dose-Response Relationship, Drug
Heart Rate / physiology
Hypertension / physiopathology*
Muscle, Smooth, Vascular / physiopathology*
Norepinephrine / pharmacology
Ovary / physiology*
Rats, Inbred SHR
Sympathetic Nervous System / physiology
Veins / physiopathology
Grant Support
63053//PHS HHS
Reg. No./Substance:

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

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