In Vivo Sarcomere Lengths Become More Non-uniform upon Activation in Intact Whole Muscle.

ABSTRACT: The sarcomere force-length relationship has been extensively used to predict muscle force potential. The common practice is to measure the mean sarcomere length (SL) in a relaxed muscle at a single location and at a given length, and this mean SL is assumed to represent the SLs at other locations across the muscle. However, in a previous study, we found that SLs are highly non-uniform across an intact passive muscle. Moreover, SL non-uniformity increases during activation in single myofibril experiments. Myofibrils lack some structural proteins that comprise an intact muscle, and therefore, the increased SL dispersion upon activation seen in myofibrils may not occur in intact whole muscle. The objectives of the current study were (i) to measure the distribution of SLs in an activated intac

SUBMITTER: Moo EK 

PROVIDER: S-EPMC5725405 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature