10.5061/DRYAD.JF35G
Altman, David
Willamette University
Minozzo, Fabio C.
McGill University
Rassier, Dilson E.
McGill University
Data from: Thixotropy and rheopexy of muscle fibers probed using
sinusoidal oscillations
Dryad
dataset
2016
actin
muscle fiber
force-dependent kinetics
blebbistatin
2016-03-27T00:00:00Z
2016-03-27T00:00:00Z
en
https://doi.org/10.1371/journal.pone.0121726
5921319989 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Length changes of muscle fibers have previously been shown to result in a
temporary reduction in fiber stiffness that is referred to as thixotropy.
Understanding the mechanism of this thixotropy is important to our
understanding of muscle function since there are many instances in which
muscle is subjected to repeated patterns of lengthening and shortening. By
applying sinusoidal length changes to one end of single permeabilized
muscle fibers and measuring the force response at the opposite end, we
studied the history-dependent stiffness of both relaxed and activated
muscle fibers. For length change oscillations greater than 1 Hz, we
observed thixotropic behavior of activated fibers. Treatment of these
fibers with EDTA and blebbistatin, which inhibits myosin-actin
interactions, quashed this effect, suggesting that the mechanism of muscle
fiber thixotropy is cross-bridge dependent. We modeled a half-sarcomere
experiencing sinusoidal length changes, and our simulations suggest that
thixotropy could arise from force-dependent cross-bridge kinetics.
Surprisingly, we also observed that, for length change oscillations less
than 1 Hz, the muscle fiber exhibited rheopexy. In other words, the
stiffness of the fiber increased in response to the length changes.
Blebbistatin and EDTA did not disrupt the rheopectic behavior, suggesting
that a non-cross-bridge mechanism contributes to this phenomenon.
Relaxed Fiber Before Treatment 1This is data from the 600A Digital
Controller (Aurora Scientific Inc.) for a relaxed muscle fiber
experiencing sinusoidal oscillationsDA_052212_f3_A.datRelaxed Fiber Before
Treatment 2This is data from the 600A Digital Controller (Aurora
Scientific Inc.) for a relaxed muscle fiber experiencing sinusoidal
oscillationsDA_052212_f4_A.datRelaxed Fiber Before Treatment 3This is data
from the 600A Digital Controller (Aurora Scientific Inc.) for a relaxed
muscle fiber experiencing sinusoidal oscillationsDA_052312_f1_A.datRelaxed
Fiber Before Treatment 4This is data from the 600A Digital Controller
(Aurora Scientific Inc.) for a relaxed muscle fiber experiencing
sinusoidal oscillationsDA_052412_f1_A.datRelaxed Fiber Before Treatment
5This is data from the 600A Digital Controller (Aurora Scientific Inc.)
for a relaxed muscle fiber experiencing sinusoidal
oscillationsDA_052412_f3_A.datRelaxed Fiber Before Treatment 6This is data
from the 600A Digital Controller (Aurora Scientific Inc.) for a relaxed
muscle fiber experiencing sinusoidal
oscillationsDA_052512_f1_A.datActivated Fiber Before Treatment 1This is
data from the 600A Digital Controller (Aurora Scientific Inc.) for an
activated muscle fiber experiencing sinusoidal
oscillationsDA_052212_f2_A.datActivated Fiber Before Treatment 2This is
data from the 600A Digital Controller (Aurora Scientific Inc.) for an
activated muscle fiber experiencing sinusoidal
oscillationsDA_052212_f3_B.datActivated Fiber Before Treatment 3This is
data from the 600A Digital Controller (Aurora Scientific Inc.) for an
activated muscle fiber experiencing sinusoidal
oscillationsDA_052212_f4_B.datActivated Fiber Before Treatment 4This is
data from the 600A Digital Controller (Aurora Scientific Inc.) for an
activated muscle fiber experiencing sinusoidal
oscillationsDA_052312_f1_B.datActivated Fiber Before Treatment 5This is
data from the 600A Digital Controller (Aurora Scientific Inc.) for an
activated muscle fiber experiencing sinusoidal
oscillationsDA_052412_f1_B.datActivated Fiber Before Treatment 6This is
data from the 600A Digital Controller (Aurora Scientific Inc.) for an
activated muscle fiber experiencing sinusoidal
oscillationsDA_052412_f3_B.datActivated Fiber Before Treatment 7This is
data from the 600A Digital Controller (Aurora Scientific Inc.) for an
activated muscle fiber experiencing sinusoidal
oscillationsDA_052512_f2_A.datActivated Fiber Before Treatment 8This is
data from the 600A Digital Controller (Aurora Scientific Inc.) for an
activated muscle fiber experiencing sinusoidal
oscillationsDA_052512_f4_A.datActivated Fiber After Treatment 1This is
data from the 600A Digital Controller (Aurora Scientific Inc.) for an
activated muscle fiber experiencing sinusoidal oscillations following
treatment with blebbistatin and EDTADA_052512_f4_G.datActivated Fiber
After Treatment 2This is data from the 600A Digital Controller (Aurora
Scientific Inc.) for an activated muscle fiber experiencing sinusoidal
oscillations following treatment with blebbistatin and
EDTADA_052312_f1_H.datRelaxed Fiber After Treatment 1This is data from the
600A Digital Controller (Aurora Scientific Inc.) for a relaxed muscle
fiber experiencing sinusoidal oscillations following treatment with
blebbistatin and EDTADA_052512_f4_H.datRelaxed Fiber After Treatment 2This
is data from the 600A Digital Controller (Aurora Scientific Inc.) for a
relaxed muscle fiber experiencing sinusoidal oscillations following
treatment with blebbistatin and EDTADA_052312_f1_I.dat