TY - JOUR
T1 - Myosin phosphorylation and force potentiation in skeletal muscle
T2 - Evidence from animal models
AU - Vandenboom, Rene
AU - Gittings, William
AU - Smith, Ian C.
AU - Grange, Robert W.
AU - Stull, James T.
N1 - Funding Information:
Acknowledgments Work in our lab supported by the Natural Sciences and Engineering Research Council of Canada (RV) (2008–2013). The important contribution of Jian Huang to these studies is also gratefully acknowledged.
PY - 2013/12
Y1 - 2013/12
N2 - The contractile performance of mammalian fast twitch skeletal muscle is history dependent. The effect of previous or ongoing contractile activity to potentiate force, i.e. increase isometric twitch force, is a fundamental property of fast skeletal muscle. The precise manifestation of force potentiation is dependent upon a variety of factors with two general types being identified; staircase potentiation referring to the progressive increase in isometric twitch force observed during low frequency stimulation while posttetanic potentiation refers to the step - like increase in isometric twitch force observed following a brief higher frequency (i.e. tetanic) stimulation. Classic studies established that the magnitude and duration of potentiation depends on a number of factors including muscle fiber type, species, temperature, sarcomere length and stimulation paradigm. In addition to isometric twitch force, more recent work has shown that potentiation also influences dynamic (i.e. concentric and/or isotonic) force, work and power at a range of stimulus frequencies in situ or in vitro, an effect that may translate to enhanced physiological function in vivo. Early studies performed on both intact and permeabilized models established that the primary mechanism for this modulation of performance was phosphorylation of myosin, a modification that increased the Ca2+ sensitivity of contraction. More recent work from a variety of muscle models indicates, however, the presence of a secondary mechanism for potentiation that may involve altered Ca2+ handling. The primary purpose of this review is to highlight these recent findings relative to the physiological utility of force potentiation in vivo.
AB - The contractile performance of mammalian fast twitch skeletal muscle is history dependent. The effect of previous or ongoing contractile activity to potentiate force, i.e. increase isometric twitch force, is a fundamental property of fast skeletal muscle. The precise manifestation of force potentiation is dependent upon a variety of factors with two general types being identified; staircase potentiation referring to the progressive increase in isometric twitch force observed during low frequency stimulation while posttetanic potentiation refers to the step - like increase in isometric twitch force observed following a brief higher frequency (i.e. tetanic) stimulation. Classic studies established that the magnitude and duration of potentiation depends on a number of factors including muscle fiber type, species, temperature, sarcomere length and stimulation paradigm. In addition to isometric twitch force, more recent work has shown that potentiation also influences dynamic (i.e. concentric and/or isotonic) force, work and power at a range of stimulus frequencies in situ or in vitro, an effect that may translate to enhanced physiological function in vivo. Early studies performed on both intact and permeabilized models established that the primary mechanism for this modulation of performance was phosphorylation of myosin, a modification that increased the Ca2+ sensitivity of contraction. More recent work from a variety of muscle models indicates, however, the presence of a secondary mechanism for potentiation that may involve altered Ca2+ handling. The primary purpose of this review is to highlight these recent findings relative to the physiological utility of force potentiation in vivo.
KW - Concentric
KW - Dynamic
KW - Eccentric
KW - Isometric twitch
KW - Myosin light chain kinase
KW - Myosin regulatory light chains
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U2 - 10.1007/s10974-013-9363-8
DO - 10.1007/s10974-013-9363-8
M3 - Review article
C2 - 24162313
AN - SCOPUS:84890115902
SN - 0142-4319
VL - 34
SP - 317
EP - 332
JO - Journal of Muscle Research and Cell Motility
JF - Journal of Muscle Research and Cell Motility
IS - 5-6
ER -