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Cross-bridge cycling in smooth muscle: a short review

Arner, Anders LU and Malmqvist, Ulf LU (1998) In Acta Physiologica Scandinavica 164(4). p.363-372
Abstract
This review is focused on the cross-bridge interaction of the organized contractile system of smooth muscle fibres. By using chemically skinned preparations the different enzymatic reactions of actin-myosin interaction have been associated with mechanical events. A rigor state has been identified in smooth muscle and the binding of ATP causes dissociation of rigor cross-bridges at rates slightly slower than those in skeletal muscle, but fast enough not to be rate-limiting for cross-bridge turn over in the muscle fibre. The release of inorganic phosphate (Pi) is associated with force generation, and this process is not rate-limiting for maximal shortening velocity (Vmax) in the fully activated muscle. The binding of ADP to myosin is strong... (More)
This review is focused on the cross-bridge interaction of the organized contractile system of smooth muscle fibres. By using chemically skinned preparations the different enzymatic reactions of actin-myosin interaction have been associated with mechanical events. A rigor state has been identified in smooth muscle and the binding of ATP causes dissociation of rigor cross-bridges at rates slightly slower than those in skeletal muscle, but fast enough not to be rate-limiting for cross-bridge turn over in the muscle fibre. The release of inorganic phosphate (Pi) is associated with force generation, and this process is not rate-limiting for maximal shortening velocity (Vmax) in the fully activated muscle. The binding of ADP to myosin is strong in the smooth muscle contractile system, a property that might be associated with the generally slow cross-bridge turn over. Both force and Vmax are modulated by the extent of myosin light chain phosphorylation. Low levels of activation are considered to be associated with the recruitment of slowly cycling dephosphorylated cross-bridges which reduces shortening velocity. The attachment of these cross-bridge states in skinned smooth muscles can be regulated by cooperative mechanisms and thin filament associated systems. Smooth muscles exhibit a large diversity in their Vmax and the individual smooth muscle tissue can alter its Vmax under physiological conditions. The diversity and the long-term modulation of phenotype are associated with changes in myosin heavy and light chain isoform expression. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Acta Physiologica Scandinavica
volume
164
issue
4
pages
363 - 372
publisher
Wiley-Blackwell
external identifiers
  • pmid:9887960
  • scopus:0032413810
ISSN
0001-6772
language
English
LU publication?
yes
id
219d2fb1-40c2-463c-8a77-cd67276dfbf4 (old id 1113741)
date added to LUP
2008-07-16 10:44:36
date last changed
2017-10-29 04:08:59
@article{219d2fb1-40c2-463c-8a77-cd67276dfbf4,
  abstract     = {This review is focused on the cross-bridge interaction of the organized contractile system of smooth muscle fibres. By using chemically skinned preparations the different enzymatic reactions of actin-myosin interaction have been associated with mechanical events. A rigor state has been identified in smooth muscle and the binding of ATP causes dissociation of rigor cross-bridges at rates slightly slower than those in skeletal muscle, but fast enough not to be rate-limiting for cross-bridge turn over in the muscle fibre. The release of inorganic phosphate (Pi) is associated with force generation, and this process is not rate-limiting for maximal shortening velocity (Vmax) in the fully activated muscle. The binding of ADP to myosin is strong in the smooth muscle contractile system, a property that might be associated with the generally slow cross-bridge turn over. Both force and Vmax are modulated by the extent of myosin light chain phosphorylation. Low levels of activation are considered to be associated with the recruitment of slowly cycling dephosphorylated cross-bridges which reduces shortening velocity. The attachment of these cross-bridge states in skinned smooth muscles can be regulated by cooperative mechanisms and thin filament associated systems. Smooth muscles exhibit a large diversity in their Vmax and the individual smooth muscle tissue can alter its Vmax under physiological conditions. The diversity and the long-term modulation of phenotype are associated with changes in myosin heavy and light chain isoform expression.},
  author       = {Arner, Anders and Malmqvist, Ulf},
  issn         = {0001-6772},
  language     = {eng},
  number       = {4},
  pages        = {363--372},
  publisher    = {Wiley-Blackwell},
  series       = {Acta Physiologica Scandinavica},
  title        = {Cross-bridge cycling in smooth muscle: a short review},
  volume       = {164},
  year         = {1998},
}