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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4 Pt 2
pubmed:dateCreated
1994-11-18
pubmed:abstractText
The calcium sensitivity of tension production and the expression of troponin I (TnI) and troponin T (TnT) isoforms in skinned neonatal (7 days after birth) and adult rat myocardium were determined. Isometric tension was measured after activation at a known resting sarcomere length in ventricular trabeculae at adult and, for the first time, neonatal ages. Analysis of the tension-pCa relationships indicates a greater calcium sensitivity (approximately 0.3 pCa units) in neonatal ventricular trabeculae compared with adult trabeculae. The maximal isometric tension-generating ability (i.e., tension-tissue cross-sectional area) is threefold greater in adult compared with neonatal trabeculae. Developmental transitions in TnI and TnT isoform expression in atrial and ventricular tissue were examined simultaneously and were found to be dissimilar. Shifts in the expression of TnT isoforms precede shifts in TnI isoforms in ventricular tissue. The opposite pattern occurs in atrial tissue, with shifts in TnI preceding those in TnT. The results show that the greater calcium sensitivity of neonatal compared with adult rat ventricular tissue is associated with developmental changes in both TnT and TnI isoform expressions. These isoform expression patterns may facilitate myocardial tension production at the neonatal stage, when the tension-generating ability of individual trabeculae is much lower than that in the adult.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H1589-96
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Tension production and thin-filament protein isoforms in developing rat myocardium.
pubmed:affiliation
Department of Physiology and Biophysics, College of Medicine, University of Illinois, Chicago 60680.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.