Linked Life Data

16940216

Source:http://linkedlifedata.com/resource/pubmed/id/16940216

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2006-9-22
pubmed:abstractText
Clinical trials failed to show a beneficial effect of postmenopausal hormone replacement therapy, whereas experimental studies in young animals reported a protective function of estrogen replacement in cardiovascular disease. Because these diverging results could in part be explained by aging effects, we compared the efficacy of estrogen substitution to modulate cardiac hypertrophy and cardiac gene expression among young (age 3 months) and senescent (age 24 months) spontaneously hypertensive rats (SHRs), which were sham operated or ovariectomized and injected with placebo or identical doses of 17beta-estradiol (E2; 2 microg/kg body weight per day) for 6 weeks (n=10/group). Blood pressure was comparable among sham-operated senescent and young SHRs and not altered by ovariectomy or E2 treatment among young or among senescent rats. Estrogen substitution inhibited uterus atrophy and gain of body weight in young and senescent ovariectomized SHRs, but cardiac hypertrophy was attenuated only in young rats. Cardiac estrogen receptor-alpha expression was lower in intact and in ovariectomized senescent compared with young SHRs and increased with estradiol substitution in aged rats. Plasma estradiol and estrone levels were lower not only in sham-operated but surprisingly also in E2-substituted senescent SHRs and associated with a reduction of hepatic 17beta-hydroxysteroid dehydrogenase type 1 enzyme activity, which converts weak (ie, estrone) into potent estrogens, such as E2. Aging attenuates the antihypertrophic effect of estradiol in female SHRs and is associated with profound alterations in cardiac estrogen receptor-alpha expression and estradiol metabolism. These observations contribute to explain the lower efficiency of estrogen substitution in senescent SHRs.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1524-4563
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
579-86
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Aging reduces the efficacy of estrogen substitution to attenuate cardiac hypertrophy in female spontaneously hypertensive rats.
pubmed:affiliation
Department of Medicine, University of Würzburg, Würzburg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't