Denervated frog skeletal muscle: Calcium content and kinetics of exchange

1976 ◽  
Vol 53 (1) ◽  
pp. 64-70 ◽  
Author(s):  
John R. Picken ◽  
Albert C. Kirby
Keyword(s):  
Skeletal Muscle ◽  
Calcium Content ◽  
Frog Skeletal Muscle ◽  
Muscle Calcium ◽  
Kinetics Of

Electromechanical Coupling II. The Effect of Perchlorate Upon Excitation-Contraction Coupling in Frog Skeletal Muscle Fibres

1982 ◽  
Vol 37 (7-8) ◽  
pp. 707-708
Author(s):  
Michael Gomolla ◽  
Gernot Gottschalk ◽  
Hans-Christoph Lüttgau
Keyword(s):  
Skeletal Muscle ◽  
Electromechanical Coupling ◽  
Muscle Fibres ◽  
Frog Skeletal Muscle ◽  
Large Shift ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
Inactivation Process ◽  
Skeletal Muscle Fibres ◽  
Kinetics Of

Abstract In single skeletal muscle Fibres perchlorate causes a large shift of the potential dependence of contraction activation to more negative potentials without a corresponding alteration in the kinetics of the inactivation process.

Determinants of relaxation rate in skinned frog skeletal muscle fibers

1998 ◽  
Vol 274 (6) ◽  
pp. C1608-C1615 ◽  
Author(s):  
Philip A. Wahr ◽  
J. David Johnson ◽  
Jack. A. Rall
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
Slow Phase ◽  
Frog Skeletal Muscle ◽  
Force Of Contraction ◽  
Thin Filaments ◽  
Fast Phase ◽  
Skeletal Muscle Fibers ◽  
Kinetics Of ◽  
Overall Kinetics

The influences of sarcomere uniformity and Ca2+ concentration on the kinetics of relaxation were examined in skinned frog skeletal muscle fibers induced to relax by rapid sequestration of Ca2+ by the photolysis of the Ca2+ chelator, diazo-2, at 10°C. Compared with an intact fiber, diazo-2-induced relaxation exhibited a faster and shorter initial slow phase and a fast phase with a longer tail. Stabilization of the sarcomeres by repeated releases and restretches during force development increased the duration of the slow phase and slowed its kinetics. When force of contraction was decreased by lowering the Ca2+concentration, the overall kinetics of relaxation was accelerated, with the slow phase being the most sensitive to Ca2+ concentration. Twitchlike contractions were induced by photorelease of Ca2+ from a caged Ca2+ (DM-Nitrophen), with subsequent Ca2+ sequestration by intact sarcoplasmic reticulum or Ca2+ rebinding to caged Ca2+. These twitchlike responses exhibited relaxation kinetics that were about twofold slower than those observed in intact fibers. Results suggest that the slow phase of relaxation is influenced by the degree of sarcomere homogeneity and rate of Ca2+ dissociation from thin filaments. The fast phase of relaxation is in part determined by the level of Ca2+ activation.

scholarly journals Kinetics of contractile activation in voltage clamped frog skeletal muscle fibers

1997 ◽  
Vol 73 (4) ◽  
pp. 1999-2011 ◽  
Author(s):  
P. Szentesi ◽  
Z. Papp ◽  
G. Szücs ◽  
L. Kovács ◽  
L. Csernoch
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
Frog Skeletal Muscle ◽  
Skeletal Muscle Fibers ◽  
Contractile Activation ◽  
Kinetics Of

scholarly journals Calcium content and exchange in frog skeletal muscle.

1975 ◽  
Vol 253 (1) ◽  
pp. 37-52 ◽  
Author(s):  
A C Kirby ◽  
B D Lindley ◽  
J R Picken
Keyword(s):  
Skeletal Muscle ◽  
Calcium Content ◽  
Frog Skeletal Muscle

The influence of D2O, perchlorate, and variation in temperature on the potential-dependent contractile function of frog skeletal muscle

1985 ◽  
Vol 63 (6) ◽  
pp. 693-703
Author(s):  
James G. Foulks ◽  
Lillian Morishita
Keyword(s):  
Skeletal Muscle ◽  
Contractile Function ◽  
Divalent Cations ◽  
Conformational Transitions ◽  
The Other ◽  
Frog Skeletal Muscle ◽  
Solvent Structure ◽  
Opposing Effects ◽  
Kinetics Of ◽  
Reduced Temperature

D2O and perchlorate manifest opposing effects on the contractile function of skeletal muscle (amplitude of twitches and maximum K contractures, potential dependence of contraction activation and inactivation), and when combined the influence of one may effectively antagonize that of the other. The ratio of perchlorate concentrations required to produce effects of equal intensity (e.g., twitch enhancement and restoration of maximum K contractures in media lacking divalent cations or containing a depressant concentration of a cationic amphipath) in H2O and D2O solutions was generally rather constant. These findings are compatible with the view that both agents can influence contractile function by virtue of their effects on solvent structure. In the absence of divalent cations, the effects of reduced temperature resemble those of D2O whereas the effects of increased temperature resemble those of the chaotropic anion. However, in other media, variation in temperature was found to result in additional nonsolvent effects so that low temperature could oppose rather than enhance the effects of D2O. These observations are discussed in terms of a model which postulates a role for solvent influences on the kinetics of two separate potential-dependent conformational transitions of membrane proteins which mediate the activation and inactivation of contraction in skeletal muscle.

scholarly journals Rev-erb-α controls skeletal muscle calcium homeostasis through myoregulin repression: implications in Duchenne Muscular Dystrophy

2021 ◽  
Author(s):  
Alexis Boulinguiez ◽  
Christian Duhem ◽  
Alicia Mayeuf-Louchart ◽  
Benoit Pourcet ◽  
Yasmine Sebti ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Duchenne Muscular Dystrophy ◽  
Calcium Homeostasis ◽  
Calcium Uptake ◽  
Calcium Content ◽  
Structure And Function ◽  
Pathological Conditions ◽  
Direct Binding ◽  
And Function ◽  
Muscle Calcium

AbstractThe sarcoplasmic reticulum (SR) plays an important role in calcium homeostasis. SR calcium mishandling is described in pathological conditions such as myopathies. Here, we investigated whether the nuclear receptor Rev-erb-α regulates skeletal muscle SR calcium homeostasis. Our data demonstrate that Rev-erbα invalidation in mice impairs SERCA-dependent SR calcium uptake. Rev-erb-α acts on calcium homeostasis by repressing the SERCA inhibitor Myoregulin, through direct binding to its promoter. Restoration of Myoregulin counteracts the effects of REV-ERB-α overexpression on SR calcium content. Interestingly, myoblasts from Duchenne myopathy patients display downregulated REV-ERBα expression, whereas pharmacological Rev-erb activation ameliorates SR calcium homeostasis, and improves muscle structure and function in dystrophic mdx/Utr+/- mice. Our findings demonstrate that Rev-erb-α regulates muscle SR calcium homeostasis, pointing to its therapeutic interest for mitigating myopathy.

scholarly journals An integratedin vitroandin situstudy of kinetics of myosin II from frog skeletal muscle

2012 ◽  
Vol 590 (5) ◽  
pp. 1227-1242 ◽  
Author(s):  
R. Elangovan ◽  
M. Capitanio ◽  
L. Melli ◽  
F. S. Pavone ◽  
V. Lombardi ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Myosin Ii ◽  
Frog Skeletal Muscle ◽  
Kinetics Of
Sign in / Sign up

Export Citation Format

Share Document