Dennis R G, Kosnik P E, Gilbert M E, Faulkner J A
Muscle Mechanics Laboratory, Institute of Gerontology, University of Michigan, Ann Arbor 48109-2007, USA.
Am J Physiol Cell Physiol. 2001 Feb;280(2):C288-95. doi: 10.1152/ajpcell.2001.280.2.C288.
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.
本研究的目的是比较由C2C12成肌细胞和10T1/2成纤维细胞系、成年C3H小鼠的原代肌肉培养物以及新生和成年Sprague-Dawley大鼠构建的三维骨骼肌结构（称为肌样）的兴奋性和收缩性。肌样长12毫米，直径0.1 - 1毫米，可通过横向电刺激兴奋并收缩产生力量。培养约30天后，测量肌样的横截面积、基强度、时值、静息基线力、抽搐力、达到峰值张力的时间、半松弛时间和峰值等长力。比肌力通过将峰值等长力除以横截面积来计算。肌样产生的比肌力是对照成年啮齿动物骨骼肌产生的比肌力的2 - 8%。由C2C12 - 10T1/2细胞构建的肌样比由成年啮齿动物培养物构建的肌样表现出更大的基强度、达到峰值张力的时间和半松弛时间，并且来自C2C12 - 10T1/2和新生大鼠细胞的肌样比来自成年啮齿动物培养物的肌样具有更大的静息基线力。
