Linked Life Data

9529164

Source:http://linkedlifedata.com/resource/pubmed/id/9529164

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1998-4-9
pubmed:abstractText
Recently, insulin-like growth factor-1 (IGF-1) has been claimed to positively influence the cardiac performance of the decompensated heart. On this basis, the effects of constitutive overexpression of IGF-1 on the mechanical behavior of myocytes were examined in transgenic mice in which the cDNA for the human IGF-1B was placed under the control of a rat alpha-myosin heavy chain promoter. In mice heterozygous for the transgene and in nontransgenic littermates at 2.5 months of age, the alterations in Ca2+ sensitivity of tension development, unloaded shortening velocity, and sarcomere compliance were measured in skinned myocytes. The quantities and state of phosphorylation of myofilament proteins in these enzymatically dissociated ventricular myocytes were also examined. The overexpression of IGF-1 was characterized by a nearly 15% reduction in myofilament isometric tension at submaximum Ca2+ levels in the physiological range, whereas developed tension at maximum activation was unchanged. In contrast, unloaded velocity of shortening was increased 39% in myocytes from transgenic mice. Moreover, resting tension in these cells was reduced by 24% to 33%. Myocytes from nontransgenic mice pretreated with IGF-1 failed to reveal changes in myofilament Ca2+ sensitivity and unloaded velocity of shortening. The quantities of C protein, troponin I, and myosin light chain-2 were comparable in transgenic and nontransgenic mice, but their endogenous state of phosphorylation increased 117%, 100%, and 100%, respectively. Troponin T content was not altered, and myosin isozymes were essentially 100% V1 in both groups of mice. In conclusion, constitutive overexpression of IGF-1 may influence positively the performance of myocytes by enhancing shortening velocity and cellular compliance.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0009-7330
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
82
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
594-603
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Effects of constitutive overexpression of insulin-like growth factor-1 on the mechanical characteristics and molecular properties of ventricular myocytes.
pubmed:affiliation
Department of Medicine, New York Medical College, Valhalla 10595, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't