Linked Life Data

436844

Source:http://linkedlifedata.com/resource/pubmed/id/436844

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1979-7-25
pubmed:abstractText
Preincubation of receptor-rich membrane fragments from Torpedo marmorata with tertiary amine local anesthetics and several toxins such as histrionicotoxin, crotoxin and cerulotoxin, modifies the amplitude and time course of the relaxation processes monitored upon rapid mixing of the membrane fragments with the fluorescent agonist, Dns-C6-Cho. In particular, the amplitude of the rapid relaxation process, which is proportional to the fraction of acetylcholine receptor sites in a high-affinity state, increases; accordingly, the rate constant of the 'slow' and 'intermediate' relaxation processes also increases up to ten times (except with histrionicotoxin) whereas in a higher range of local anesthetic concentrations the rate constant of the 'rapid' relaxation process decreases. The data are accounted for by a two-state model of the acetylcholine regulator, assuming distinct binding sites for cholinergic agonists and local anesthetics and allosteric interactions between these two classes of sites; local anesthetics stabilize the regulator in a high-affinity state for agonists even in the absence of agonist, and modify the rate constants for th interconversions between the low-affinity and high-affinity states. The model accounts for the 'slow' fluorescence increase monitored upon addition of local anesthetics to a suspension of receptor-rich membranes supplemented with trace amounts of Dns-C6-Cho. The effect of local anesthetics on the apparent rate constant of the 'rapid' relaxation process can be accounted for on the basis of an additional low-affinity binding of local anesthetics to the acetylcholine receptor site. Finally the increase of the apparent rate constant of the 'intermediate' relaxation process can be simply accounted for by assuming the existence of a third state, corresponding to the 'active' state, to which local anesthetics bind and block ionic transport.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
94
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
281-96
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1979
pubmed:articleTitle
Fast kinetic studies on the allosteric interactions between acetylcholine receptor and local anesthetic binding sites.
pubmed:publicationType
Journal Article