title: The trabecula culture system: a novel technique to study contractile parameters over a multiday time period.
abstract: In the intact heart, various triggers induce alterations in gene expression that impact on contractile function. Because changes in gene expression reflect altered protein expression patterns after 12-48 h, we developed a system in which intact twitching cardiac trabeculae can be studied for multiday periods. Right ventricular trabeculae from pentobarbital sodium anesthetized rabbits were mounted in a sterile, closed muscle chamber. Over the first 48 h, developed force (Fdev) did not significantly change: 102.3 and 98.9% of the initial Fdev was observed after 24 and 48 h, respectively (n = 8). Also, neither diastolic force, time from peak to 50% relaxation (RT50), nor protein synthesis measured by a [3H]leucine incorporation assay changed significantly over time. Contractile response after > 48 h to an increase in extracellular calcium concentration (1.8 to 2.5 mM; Fdev increased 43.5%, n = 2) or to 1 microM isoproterenol (Fdev increased 138.6% and RT50 decreased 34.9%, n = 2) was similar to those observed in freshly dissected preparations. In conclusion, this system can investigate contractile function of multicellular preparations under well-defined physiological conditions after events that alter gene and consequent protein expression.
authors.affiliation: Medizinische Klinik III, Universität Freiburg, Germany.
authors.forename: P M
authors.initials: PM
authors.lastname: Janssen
authors.forename: S E
authors.initials: SE
authors.lastname: Lehnart
authors.forename: J
authors.initials: J
authors.lastname: Prestle
authors.forename: J C
authors.initials: JC
authors.lastname: Lynker
authors.forename: P
authors.initials: P
authors.lastname: Salfeld
authors.forename: H
authors.initials: H
authors.lastname: Just
authors.forename: G
authors.initials: G
authors.lastname: Hasenfuss
mesh_terms: D000818:Animals; D002118:Calcium / Q000502:physiology; D002316:Cardiotonic Agents / Q000494:pharmacology; D046508:Culture Techniques / Q000379:methods*; D005786:Gene Expression Regulation / Q000502:physiology*; D006321:Heart / Q000502:physiology*; D007545:Isoproterenol / Q000494:pharmacology; D009124:Muscle Proteins / Q000096:biosynthesis* / Q000235:genetics; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology*; D009206:Myocardium / Q000166:cytology; D011817:Rabbits; D013997:Time Factors
chemical_list: D002316:Cardiotonic Agents; D009124:Muscle Proteins; D007545:Isoproterenol; D002118:Calcium