Comparison of the effects of 2,3-butanedione monoxime on force production, myosin light chain phosphorylation and chemical energy usage in intact and permeabilized smooth and skeletal muscles

1994 ◽  
Vol 15 (4) ◽  
pp. 457-472 ◽  
Author(s):  
Marion J. Siegman ◽  
Susan U. Mooers ◽  
Thomas B. Warren ◽  
David M. Warshaw ◽  
Mitsuo Ikebe ◽  
...  
Keyword(s):  
Light Chain ◽  
Skeletal Muscles ◽  
Myosin Light Chain ◽  
Force Production ◽  
Chemical Energy ◽  
Myosin Light Chain Phosphorylation ◽  
Energy Usage ◽  
Butanedione Monoxime

scholarly journals Nerve influence on myosin light chain phosphorylation in slow and fast skeletal muscles

FEBS Journal ◽  
2005 ◽  
Vol 272 (22) ◽  
pp. 5771-5785 ◽  
Author(s):  
Cyril Bozzo ◽  
Barbara Spolaore ◽  
Luana Toniolo ◽  
Laurence Stevens ◽  
Bruno Bastide ◽  
...  
Keyword(s):  
Light Chain ◽  
Skeletal Muscles ◽  
Myosin Light Chain ◽  
Myosin Light Chain Phosphorylation

Myosin light chain phosphorylation during contraction of chicken fast and slow skeletal muscles

1983 ◽  
Vol 225 (2) ◽  
pp. 692-703 ◽  
Author(s):  
Kate Bárány ◽  
Ronald F. Ledvora ◽  
David L. Vander Meulen ◽  
Michael Bárány
Keyword(s):  
Light Chain ◽  
Skeletal Muscles ◽  
Myosin Light Chain ◽  
Myosin Light Chain Phosphorylation

scholarly journals Arteriolar vasodilation involves actin depolymerization

2018 ◽  
Vol 315 (2) ◽  
pp. H423-H428
Author(s):  
Philip S. Clifford ◽  
Brian S. Ferguson ◽  
Jeffrey L. Jasperse ◽  
Michael A. Hill
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Sodium Nitroprusside ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Muscle Relaxation ◽  
Nitric Oxide Donor ◽  
Smooth Muscle Relaxation ◽  
Myosin Light Chain Phosphorylation ◽  
Actin Depolymerization

It is generally assumed that relaxation of arteriolar vascular smooth muscle occurs through hyperpolarization of the cell membrane, reduction in intracellular Ca2+ concentration, and activation of myosin light chain phosphatase/inactivation of myosin light chain kinase. We hypothesized that vasodilation is related to depolymerization of F-actin. Cremaster muscles were dissected in rats under pentobarbital sodium anesthesia (50 mg/kg). First-order arterioles were dissected, cannulated on glass micropipettes, pressurized, and warmed to 34°C. Internal diameter was monitored with an electronic video caliper. The concentration of G-actin was determined in flash-frozen intact segments of arterioles by ultracentrifugation and Western blot analyses. Arterioles dilated by ~40% of initial diameter in response to pinacidil (1 × 10−6 mM) and sodium nitroprusside (5 × 10−5 mM). The G-actin-to-smooth muscle 22α ratio was 0.67 ± 0.09 in arterioles with myogenic tone and increased significantly to 1.32 ± 0.34 ( P < 0.01) when arterioles were dilated with pinacidil and 1.14 ± 0.18 ( P < 0.01) with sodium nitroprusside, indicating actin depolymerization. Compared with control vessels (49 ± 5%), the percentage of phosphorylated myosin light chain was significantly reduced by pinacidil (24 ± 2%, P < 0.01) but not sodium nitroprusside (42 ± 4%). These findings suggest that actin depolymerization is an important mechanism for vasodilation of resistance arterioles to external agonists. Furthermore, pinacidil produces smooth muscle relaxation via both decreases in myosin light chain phosphorylation and actin depolymerization, whereas sodium nitroprusside produces smooth muscle relaxation primarily via actin depolymerization. NEW & NOTEWORTHY This article adds to the accumulating evidence on the contribution of the actin cytoskeleton to the regulation of vascular smooth muscle tone in resistance arterioles. Actin depolymerization appears to be an important mechanism for vasodilation of resistance arterioles to pharmacological agonists. Dilation to the K+ channel opener pinacidil is produced by decreases in myosin light chain phosphorylation and actin depolymerization, whereas dilation to the nitric oxide donor sodium nitroprusside occurs primarily via actin depolymerization. Listen to this article’s corresponding podcast at https://ajpheart.podbean.com/e/vascular-smooth-muscle-actin-depolymerization/ .

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