Jostarndt-Fögen K, Puntschart A, Hoppeler H, Billeter R
Institute of Anatomy, University of Berne, Switzerland.
Acta Physiol Scand. 1998 Nov;164(3):299-308. doi: 10.1046/j.1365-201X.1998.00444.x.
The fibre-type specific expression patterns of fast and slow isoforms of essential (alkali) myosin light chains (ELC) was analysed in trained, untrained and pathological human muscles. Biopsies from m. vastus lateralis of moderately trained and untrained persons, as well as highly trained endurance and strength athletes were analysed, by in situ hybridization, for the expression of the 'fast' ELC 1f/3f and the 'slow' ELC 1 sb. We wanted to investigate if changes in the fibre-type specific ELC mRNA pattern could be used as markers for training adaptation, especially, if the mRNA of the slow ELC 1sb isoform would appear in type IIA fibres as a result of endurance training (Baumann et al. 1987). We found the fast/slow ELC expression patterns in the fibre types to be remarkably stable. Physiological stress, even high training loads, did not affect it. No IIA fibres expressing ELC 1sb mRNA were found. They could be detected, however, in pathological muscle samples, where fast/slow ELC patterns not found in normal muscles were frequent. Our data suggest that in healthy muscles, only a subset of the theoretically possible combinations of myosin heavy and light chain isoforms are expressed at the level of their mRNAs.
在经过训练、未经过训练以及患有疾病的人体肌肉中，分析了必需（碱性）肌球蛋白轻链（ELC）快速和慢速亚型的纤维类型特异性表达模式。通过原位杂交技术，对中度训练和未训练者的股外侧肌活检样本，以及高水平耐力和力量运动员的股外侧肌活检样本进行分析，以检测“快速”ELC 1f/3f和“慢速”ELC 1sb的表达情况。我们想要研究纤维类型特异性ELC mRNA模式的变化是否可作为训练适应性的标志物，特别是耐力训练后，慢速ELC 1sb亚型的mRNA是否会出现在IIA型纤维中（Baumann等人，1987年）。我们发现纤维类型中快速/慢速ELC的表达模式非常稳定。生理应激，即使是高强度训练负荷，也不会对其产生影响。未发现表达ELC 1sb mRNA的IIA型纤维。然而，在病理肌肉样本中可以检测到它们，在这些样本中，正常肌肉中未发现的快速/慢速ELC模式很常见。我们的数据表明，在健康肌肉中，只有一部分理论上可能的肌球蛋白重链和轻链亚型组合在mRNA水平上表达。
