Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2005-11-14
pubmed:abstractText
Recent data suggest that beta-adrenergic receptor subtypes couple differentially to signaling pathways regulating cardiac function vs. cardiac remodeling. To dissect the roles of beta1- vs. beta2-receptors in the pathogenesis of cardiomyopathy, doxorubicin was administered to beta1, beta2, and beta1/beta2 knockout (-/-) and wild-type mice. Expression and activation of MAPKs were measured. Wild-type and beta1-/- mice showed no acute cardiovascular effects, whereas beta2-/- mice all died within 30 min. The additional deletion of the beta1-receptor (beta1/beta2-/-) totally rescued this toxicity. beta2-/- mice developed decreased contractile function, hypotension, QTc prolongation, and ST segment changes and a 20-fold increase in p38 MAPK activity not seen in the other genotypes. The MAPK inhibitor SB-203580 rescued beta2-/- mice from this acute toxicity. The enhanced toxicity in beta2-/- mice was also recapitulated in wild-type mice with the beta2-selective antagonist ICI-118,551, although the rescue effect of the beta1-deletion was not recapitulated using the beta1-selective antagonist metoprolol or the nonselective beta-antagonist propranolol. These data suggest that beta2-adrenergic receptors play a cardioprotective role in the pathogenesis of cardiomyopathy, whereas beta1-adrenergic receptors mediate at least some of the acute cardiotoxicity of anthracyclines. Differential activation of MAPK isoforms, previously shown in vitro to regulate beta-agonist as well as doxorubicin cardiotoxicity, appears to play a role in mediating the differential effects of these beta-adrenergic receptor subtypes in vivo.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0363-6135
pubmed:author
pubmed:issnType
Print
pubmed:volume
289
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H2441-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Differential cardioprotective/cardiotoxic effects mediated by beta-adrenergic receptor subtypes.
pubmed:affiliation
Dept. of Pediatrics, 750 Welch Rd., Suite 305, Palo Alto, CA 94304, USA. danb@stanford.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural