title: Excitability and contractility of skeletal muscle engineered from primary cultures and cell lines.
abstract: The purpose of this study was to compare the excitability and contractility of three-dimensional skeletal muscle constructs, termed myooids, engineered from C2C12 myoblast and 10T1/2 fibroblast cell lines, primary muscle cultures from adult C3H mice, and neonatal and adult Sprague-Dawley rats. Myooids were 12 mm long, with diameters of 0.1-1 mm, were excitable by transverse electrical stimulation, and contracted to produce force. After approximately 30 days in culture, myooid cross-sectional area, rheobase, chronaxie, resting baseline force, twitch force, time to peak tension, one-half relaxation time, and peak isometric force were measured. Specific force was calculated by dividing peak isometric force by cross-sectional area. The specific force generated by the myooids was 2-8% of that generated by skeletal muscles of control adult rodents. Myooids engineered from C2C12-10T1/2 cells exhibited greater rheobase, time to peak tension, and one-half relaxation time than myooids engineered from adult rodent cultures, and myooids from C2C12-10T1/2 and neonatal rat cells had greater resting baseline forces than myooids from adult rodent cultures.
authors.affiliation: Muscle Mechanics Laboratory, Institute of Gerontology, University of Michigan, Ann Arbor 48109-2007, USA. bobden@umich.edu
authors.forename: R G
authors.initials: RG
authors.lastname: Dennis
authors.forename: P E
authors.initials: PE
authors.lastname: Kosnik
authors.forename: M E
authors.initials: ME
authors.lastname: Gilbert
authors.forename: J A
authors.initials: JA
authors.lastname: Faulkner
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D021522:Bioartificial Organs; D002478:Cells, Cultured; D005347:Fibroblasts / Q000502:physiology*; D007537:Isometric Contraction / Q000502:physiology*; D051379:Mice; D018482:Muscle, Skeletal / Q000502:physiology*; D051381:Rats