Linked Life Data

11049872

Source:http://linkedlifedata.com/resource/pubmed/id/11049872

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2000-11-15
pubmed:abstractText
Aging is associated with altered autonomic control of cardiovascular function, but baroreflex function in animal models of aging remains controversial. In this study, pressor and depressor agent-induced reflex bradycardia and tachycardia were attenuated in conscious old (24 mo) rats [57 and 59% of responses in young (10 wk) Wistar rats, respectively]. The intrinsic heart rate (HR, 339 +/- 5 vs. 410 +/- 10 beats/min) was reduced in aged animals, but no intergroup differences in resting mean arterial blood pressure (MAP, 112 +/- 3 vs. 113 +/- 5 mmHg) or HR (344 +/- 9 vs. 347 +/- 9 beats/min) existed between old and young rats, respectively. The aged group also exhibited a depressed (49%) parasympathetic contribution to the resting HR value (vagal effect) but preserved sympathetic function after intravenous methylatropine and propranolol. An implantable electrode revealed tonic renal sympathetic nerve activity (RSNA) was similar between groups. However, old rats showed impaired baroreflex control of HR and RSNA after intravenous nitroprusside (-0.63 +/- 0. 18 vs. -1.84 +/- 0.4 bars x cycle(-1) x mmHg(-1) x s(-1)). Therefore, aging in rats is associated with 1) preserved baseline MAP, HR, and RSNA, 2) impaired baroreflex control of HR and RSNA, and 3) altered autonomic control of resting HR.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0363-6119
pubmed:author
pubmed:issnType
Print
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
R1865-71
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Aging and baroreflex control of RSNA and heart rate in rats.
pubmed:affiliation
Hypertension Unit, Heart Institute-InCor, Medical School, University of São Paulo, São Paulo, São Paulo 5403-000, Brazil. hipirigoyen@incor.usp.br
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't