Increase in the degree of coexpression of myosin heavy chain isoforms in skeletal muscle fibers of the very old.

@article{Andersen1999IncreaseIT,
  title={Increase in the degree of coexpression of myosin heavy chain isoforms in skeletal muscle fibers of the very old.},
  author={J L Andersen and Gerasimos Terzis and Ann Isabel Kryger},
  journal={Muscle & nerve},
  year={1999},
  volume={22 4},
  pages={449-54}
}
Myosin heavy chain (MHC) isoform composition was determined in 2264 single skeletal muscle fibers from vastus lateralis muscle of a group (n = 12) of very old subjects (average age, 88 years). The number of fibers containing only MHC I, IIA, or IIX was 19.9%, 27.2%, and 0.3%, respectively. Surprisingly, 28.5% of the fibers displayed coexpression of both MHC I and IIA, a phenotype that is present in younger adults in very small percentages. Among these fibers coexpressing MHC I and IIA, the… CONTINUE READING