Linked Life Data

8755999

Source:http://linkedlifedata.com/resource/pubmed/id/8755999

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-12-12
pubmed:abstractText
It has been proposed that chronic treatment with growth hormone (GH) or insulin-like growth factor-I (IGF-I) in the rat may enhance cardiac function in vivo. To confirm these findings and elucidate the mechanisms by which cardiac function is modulated, we studied isolated buffer-perfused rat hearts after 4 weeks of treatment with high doses of GH and IGF-I alone or in combination. Mechanical parameters were measured at 50% of the intracardiac balloon volume at which maximal developed pressure (DevP) occurred. EC50 of the force-Ca2+ relationship and maximal Ca(2+)-activated systolic wall stress (max sigma s) were assessed by increasing Ca2+ in the perfusate in a stepwise fashion and plotting systolic wall stress (sigma s) versus intracellular peak systolic Ca2+, measured by the aequorin bioluminescence method. We found a marked increase of systolic pressure (Ps), DevP, and (+dP/dt)/DevP in the treated groups compared with the control group. The combination group showed a blunted effect. sigma s was increased in all treated groups for a perfusate Ca2+ concentration of > 1.5 mmol/L. The enhanced systolic performance can be explained by an increase of the overall Ca2+ responsiveness due to an increased maximal response to Ca2+ even though the EC50 of the Ca(2+)-dose response was also slightly increased. Ps was further enhanced by an increase of the relative wall thickness induced by the treatment. Diastolic pressure, diastolic Ca2+, and the amplitude and time course of the Ca2+ transient were not influenced by any treatment protocol. All treatments caused increases of body and heart weight. These data support the hypothesis that both IGF-I and GH directly affect cardiac performance by altering cardiac geometry as well as by enhancing max sigma s.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0009-7330
pubmed:author
pubmed:issnType
Print
pubmed:volume
79
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
227-36
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Exogenously administered growth hormone and insulin-like growth factor-I alter intracellular Ca2+ handling and enhance cardiac performance. In vitro evaluation in the isolated isovolumic buffer-perfused rat heart.
pubmed:affiliation
Charles A. Dana Research Institute, Department of Medicine, Beth Israel Hospital, Boston, MA 02215, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't