Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2000-5-1
pubmed:abstractText
To examine the influence of chronic mechanical stretch on functional behavior of cardiac myocytes, we reconstituted embryonic chick or neonatal rat cardiac myocytes to a 3-dimensional engineered heart tissue (EHT) by mixing freshly isolated cells with neutralized collagen I and culturing them between two Velcro-coated silicone tubes, held at a fixed distance with a metal spacer. After 4 days, EHTs were subjected to a phasic unidirectional stretch for 6 days in serum-containing medium. Compared to unstretched controls, RNA/DNA and protein/cell ratios increased by 100% and 50%, respectively. ANF mRNA and alpha-sarcomeric actin increased by 98% and 40%, respectively. Morphologically, stretched EHTs exhibited improved organization of cardiac myocytes into parallel arrays of rod-shaped cells, increased cell length and width, longer myofilaments, and increased mitochondrial density. Thus, stretch induced phenotypic changes, generally referred to as hypertrophy. Concomitantly, force of contraction was two- to fourfold higher both under basal conditions and after stimulation with calcium or the beta-adrenergic agonist isoprenaline. Contraction kinetics were accelerated with a 14-44% decrease in twitch duration under all those conditions. In summary, we have developed a new in vitro model that allows morphological, molecular, and functional consequences of stretch to be studied under defined conditions. The main finding was that stretch of EHTs induced cardiac myocyte hypertrophy, which was accompanied by marked improvement of contractile function.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0892-6638
pubmed:author
pubmed:issnType
Print
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
669-79
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:10744624-Adrenergic beta-Agonists, pubmed-meshheading:10744624-Animals, pubmed-meshheading:10744624-Animals, Newborn, pubmed-meshheading:10744624-Biomedical Engineering, pubmed-meshheading:10744624-Calcium, pubmed-meshheading:10744624-Cell Count, pubmed-meshheading:10744624-Cell Size, pubmed-meshheading:10744624-Chick Embryo, pubmed-meshheading:10744624-DNA, pubmed-meshheading:10744624-Gene Expression, pubmed-meshheading:10744624-Heart, pubmed-meshheading:10744624-Isoproterenol, pubmed-meshheading:10744624-Microscopy, Electron, pubmed-meshheading:10744624-Models, Cardiovascular, pubmed-meshheading:10744624-Myocardial Contraction, pubmed-meshheading:10744624-Myocardium, pubmed-meshheading:10744624-RNA, pubmed-meshheading:10744624-Rats, pubmed-meshheading:10744624-Rats, Wistar, pubmed-meshheading:10744624-Stress, Mechanical
pubmed:year
2000
pubmed:articleTitle
Chronic stretch of engineered heart tissue induces hypertrophy and functional improvement.
pubmed:affiliation
Institute of Experimental and Clinical Pharmacology and Toxicology, University-Hospital Eppendorf, Hamburg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't