Document Detail


High-calcium diet reduces blood pressure, blood volume and preserves vasorelaxation in oral contraceptive-treated female rats.
MedLine Citation:
PMID:  20036339     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Cardiovascular complications are the major clinical challenges among users of synthetic steroids in oral contraceptive (OC) formulations. Interventions that reduce blood volume and improve vasorelaxation have been shown to reduce hypertension and the associated risk factors. The aim of the present study was to investigate the influence of increasing dietary calcium from 0.9 to 3.0% on the development of OC-induced high blood pressure and associated changes in female Sprague-Dawley rats treated with a combination of OC steroids (1 microg ethinyl estradiol and 10 microg norgestrel; p.o.) daily for 10 weeks. Results showed that OC administration led to significant increases in blood pressure, blood volume and cardiac weight. Conversely, OC caused significant reductions in body weight, urinary excretion of water, plasma levels of calcium, 17beta-estradiol and progesterone. Increased dietary calcium attenuated the elevation in blood pressure induced by OC and abrogated the associated changes in blood volume, cardiac weight, plasma calcium and urinary excretion of water. The endothelium-dependent relaxation responses to acetylcholine and endothelium-independent relaxation responses to sodium nitroprusside in noradrenaline-precontracted aortic rings were not significantly different among the groups. The results indicate that increased calcium intake abrogated the development of high blood pressure and associated increased blood volume and cardiac weight during OC treatment. The beneficial effect of increased dietary calcium during OC use may be explained by improved diuretic and preserved vasorelaxant responses.
Authors:
Lawrence A Olatunji; Ayodele O Soladoye
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-12-24
Journal Detail:
Title:  Vascular pharmacology     Volume:  52     ISSN:  1879-3649     ISO Abbreviation:  Vascul. Pharmacol.     Publication Date:    2010 Jan-Feb
Date Detail:
Created Date:  2010-02-17     Completed Date:  2010-09-29     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101130615     Medline TA:  Vascul Pharmacol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  95-100     Citation Subset:  IM    
Copyright Information:
2009 Elsevier Inc. All rights reserved.
Affiliation:
Department of Physiology, College of Health Sciences, University of Ilorin, P.M.B. 1515 Ilorin 240001, Nigeria. tunjilaw@unilorin.edu.ng
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure / drug effects*,  physiology
Blood Volume / drug effects*,  physiology
Calcium / administration & dosage,  blood
Calcium, Dietary / administration & dosage*
Contraceptives, Oral / adverse effects*,  blood
Female
Hypertension / chemically induced,  drug therapy,  physiopathology
Rats
Rats, Sprague-Dawley
Treatment Outcome
Vasodilation / drug effects*,  physiology
Chemical
Reg. No./Substance:
0/Calcium, Dietary; 0/Contraceptives, Oral; 7440-70-2/Calcium

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


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