Further studies on the effects of myosin P-light chain phosphorylation on contractile properties of skinned cardiac fibres

1986 ◽  
Vol 81 (6) ◽  
pp. 611-619 ◽  
Author(s):  
I. Morano ◽  
H. Arndt ◽  
C. Bächle-Stolz ◽  
J. C. Rüegg
Keyword(s):  
Light Chain ◽  
Contractile Properties ◽  
Skinned Cardiac Fibres

Determinants of the contractile properties in the embryonic chicken gizzard and aorta

2000 ◽  
Vol 279 (6) ◽  
pp. C1722-C1732 ◽  
Author(s):  
Ozgur Ogut ◽  
Frank V. Brozovich
Keyword(s):  
Smooth Muscle ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Smooth Muscles ◽  
Contractile Properties ◽  
In Vitro Motility ◽  
Force Maintenance ◽  
Isoform Expression ◽  
Force Activation

Smooth muscle is generally grouped into two classes of differing contractile properties. Tonic smooth muscles show slow rates of force activation and relaxation and slow speeds of shortening ( V max) but force maintenance, whereas phasic smooth muscles show poor force maintenance but have fast V max and rapid rates of force activation and relaxation. We characterized the development of gizzard and aortic smooth muscle in embryonic chicks to identify the cellular determinants that define phasic (gizzard) and tonic (aortic) contractile properties. Early during development, tonic contractile properties are the default for both tissues. The gizzard develops phasic contractile properties between embryonic days ( ED) 12 and 20, characterized primarily by rapid rates of force activation and relaxation compared with the aorta. The rapid rate of force activation correlates with expression of the acidic isoform of the 17-kDa essential myosin light chain (MLC17a). Previous data from in vitro motility assays (Rover AS, Frezon Y, and Trybus KM. J Muscle Res Cell Motil 18: 103–110, 1997) have postulated that myosin heavy chain (MHC) isoform expression is a determinant for V max in intact tissues. In the current study, differences in V max did not correlate with previously published differences in MHC or MLC17a isoforms. Rather, V max was increased with thiophosphorylation of the 20-kDa regulatory myosin light chain (MLC20) in the gizzard, suggesting that a significant internal load exists. Furthermore, V max in the gizzard increased during postnatal development without changes in MHC or MLC17 isoforms. Although the rate of MLC20 phosphorylation was similar at ED 20, the rate of MLC20 dephosphorylation was significantly higher in the gizzard versus the aorta, correlating with expression of the M130 isoform of the myosin binding subunit in the myosin light chain phosphatase (MLCP) holoenzyme. These results indicate that unique MLCP and MLC17 isoform expression marks the phasic contractile phenotype.

scholarly journals EFFECT OE DENERVATION ON CONTRACTILE PROPERTIES AND MYOSIN LIGHT CHAIN PHOSPHORYLATION IN RAT PAST-TWITCH SKELETAL MUSCLES

1988 ◽  
Vol 9 (5) ◽  
pp. 353-360 ◽  
Author(s):  
SHIGEKI MATSUSHITA ◽  
SHIN’ICHI TAKEDA ◽  
SHIN’ICHI SHOJI ◽  
NOBUO YANAGISAWA
Keyword(s):  
Light Chain ◽  
Myosin Light Chain ◽  
Contractile Properties ◽  
Myosin Light Chain Phosphorylation

373: The Contractile Properties of Detrusor Smooth Muscle in Cloacal Exstrophy

2007 ◽  
Vol 177 (4S) ◽  
pp. 124-124
Author(s):  
Navroop S. Johal ◽  
Peter M. Cuckow ◽  
Christopher H. Fry
Keyword(s):  
Smooth Muscle ◽  
Contractile Properties ◽  
Detrusor Smooth Muscle ◽  
Cloacal Exstrophy

165: Myosin Light Chain Dephosphorylation is Associated with Bladder Compliance

2006 ◽  
Vol 175 (4S) ◽  
pp. 53-53
Author(s):  
Andy Y. Chang ◽  
Stephen A. Zderic ◽  
Douglas A. Canning ◽  
Samuel Chacko
Keyword(s):  
Light Chain ◽  
Myosin Light Chain ◽  
Bladder Compliance
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