Linked Life Data

2535795

Source:http://linkedlifedata.com/resource/pubmed/id/2535795

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1989-2-9
pubmed:abstractText
The influence of selective (milrinone: 10, 50, 100 microM) and nonselective phosphodiesterase (isobutylmethylxanthine: 0.1, 10, 100 microM) inhibitors and beta-adrenergic stimulation (isoproterenol: 0.01, 0.1 microM) on phospholamban and myofibrillar protein phosphorylation was studied in guinea pig hearts perfused with [32P]orthophosphate. Changes in protein phosphorylation were compared to alterations in tissue cyclic AMP (cAMP) levels and positive inotropic effects induced by these agents. Isoproterenol (0.01 microM), milrinone (50 microM), and isobutylmethylxanthine (100 microM) all produced similar, twofold increases in dP/dt and -dP/dt but only stimulation with isobutylmethylxanthine and isoproterenol was associated with significant increases in phospholamban phosphorylation. At these equipotent doses, the effects of isobutylmethylxanthine were associated with higher increases (3.1-fold) in cAMP than those observed with isoproterenol (twofold). Milrinone (50 microM) produced a 2.5-fold increase in cAMP levels but failed to change phospholamban phosphorylation. Higher doses of milrinone (100 microM) resulted in relatively high (4.1-fold) cAMP levels, and this was associated with increased (1.5-fold) phosphorylation of phospholamban. Phosphorylation of troponin I was significantly increased at 0.01 microM and 0.1 microM isoproterenol, while phosphorylation of C protein was observed only at 0.1 microM isoproterenol. Isobutylmethylxanthine and milrinone did not significantly increase phosphorylation of either troponin I or C protein at any of the doses studied. These findings indicate that cardiotonic agents acting via the cAMP pathway may produce similar inotropic responses at different levels of cAMP and phosphorylation of sarcoplasmic reticulum and myofibrillar proteins.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0009-7330
pubmed:author
pubmed:issnType
Print
pubmed:volume
64
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
104-11
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Inotropic responses to isoproterenol and phosphodiesterase inhibitors in intact guinea pig hearts: comparison of cyclic AMP levels and phosphorylation of sarcoplasmic reticulum and myofibrillar proteins.
pubmed:affiliation
Department of Pharmacology, University of Cincinnati College of Medicine, OH 45267-0575.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.