Linked Life Data

3429640

Source:http://linkedlifedata.com/resource/pubmed/id/3429640

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1988-3-15
pubmed:abstractText
The mechanical events following release of ATP from P3-1-(2-nitro)phenylethyladenosine-5'-triphosphate (caged-ATP) in skinned guinea pig taenia coli smooth muscle in rigor were investigated. A rigor force of about 25-35% of the maximal active force was obtained by removing ATP at the plateau of a maximal active contraction. In the rigor solution free-Mg2+ was 2 mM, ionic strength 90 mM and pH 7.0. When caged-ATP (12.5 mM) was diffused into the preparation there was no change in the rigor force. Photolytic production of about 2 mM ATP was achieved with a xenon flash lamp. Following illumination, force decreased with an approximate initial rate constant of 0.7 s-1. The rate of relaxation was increased in the presence of inorganic phosphate (at 3 mM: 1.3 s-1; 10 mM: 2.2 s-1). At higher Mg2+ concentrations the rate of relaxation was slower (5 mM: 0.2 s-1) and at lower concentrations the rate was faster (0.5 mM: 1.2 s-1). An increased rate of relaxation was observed when ionic strength was increased to 150 mM (2.2 s-1). Phosphate increased the rate of relaxation at the different levels of Mg2+ (0.5-10 mM) and ionic strength (90, 150 mM). In preparations shortened (by 1-3%) to give reduced rigor force, a small transient increase in tension was recorded after ATP release. In comparison to the rates of ATP-induced dissociation of actomyosin in solution, reported in the literature, the rate of relaxation from rigor is slower. This may reflect a slow rigor cross-bridge dissociation or mechanical interactions not associated with cross-bridges in the muscle fibre.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0142-4319
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
377-85
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Relaxation of chemically skinned guinea pig taenia coli smooth muscle from rigor by photolytic release of adenosine-5'-triphosphate.
pubmed:affiliation
Physiologisches Institut der Universität Heidelberg, F.R.G.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't