Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4 Pt 1
pubmed:dateCreated
1986-5-15
pubmed:abstractText
The time course and the steady-state calcium dependence of myosin phosphorylation and isotonic shortening velocity were studied during contraction and relaxation of canine tracheal smooth muscle. Dephosphorylation of myosin coincided with the decay of isotonic shortening velocity during rapid relaxation following agonist washout. However, the decay of shortening velocity preceded dephosphorylation during a slow relaxation induced by Ca2+-free physiological salt solution (PSS). Carbachol dose-response curves for isometric stress development and myosin phosphorylation were superimposable but shifted to the left of the shortening velocity dose-response. The steady-state Ca2+ dependence of myosin phosphorylation was defined using carbachol and K+ as agonists. There was a significant dissociation of dephosphorylation and relaxation following a stepwise reduction of extracellular CaCl2 concentration. This result was related to muscarinic activation because the dissociation of relaxation and dephosphorylation was reduced by atropine in muscles stimulated with K+. Myosin phosphorylation was completely dissociated from contraction when muscles were stimulated with carbachol in Ca2+-free PSS and contracted by readmission of CaCl2. Mechanisms in addition to myosin phosphorylation appear to regulate airway muscle tone and shortening velocity, and two possibilities are discussed.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
250
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C597-604
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Calcium dependence of myosin phosphorylation and airway smooth muscle contraction and relaxation.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't