Linked Life Data

2253703

Source:http://linkedlifedata.com/resource/pubmed/id/2253703

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
1991-1-22
pubmed:abstractText
Muscarinic acetylcholine receptors were identified by the specific binding of [H](-)quinuclidinylbenzilate [( 3H](-)QNB) and [3H]oxotremorine-M [( 3H]Oxo-M), to membranes isolated from the sino-atrial (SA) node and right atrium (RA) of bovine heart. The density of [3H](-)QNB binding sites was greater in the SA node compared to the RA. Specific [3H](-)QNB binding was saturable and occurred to a single population of binding sites in both regions. The binding of antagonists, as assessed by competition with [3H](-)QNB, also occurred to a single population of sites; the binding affinities of all antagonists were similar in either region. Agonist competition curves, except for McN-A-343, were complex and computer analyses indicated that agonists bound to at least two populations of binding sites that differed in affinity. The proportion of high-affinity agonist binding sites was consistently greater in the SA nodal, relative to the RA membranes, while the affinity of the high-affinity agonist binding sites to a given agonist was essentially similar in either region. The high-affinity binding of [3H]Oxo-M was saturable and occurred to a single population of sites. The maximal binding of [3H]Oxo-M in the SA nodal membranes was higher than in the RA membranes. Guanine nucleotides and N-ethylmaleimide (NEM) markedly decreased [3H]Oxo-M binding; NEM did not appear to influence guanine nucleotide-dependent decrease in [3H]Oxo-M binding. Phospholipase A2 decreased both [3H](-)QNB and [3H]Oxo-M specific binding, the latter being affected to a greater extent. Phospholipase C also decreased [3H](-)QNB and [3H]Oxo-M binding, although to a lesser degree compared to phospholipase A2. Either lipase, however, increased the guanine nucleotide-sensitive agonist binding. Analysis of [3H](-)QNB binding to microsomal subfractions showed that binding sites were enriched in the light plasma membrane fractions that were also enriched in pertussis toxin sensitive guanine nucleotide binding proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0014-2999
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
189
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
201-15
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Muscarinic acetylcholine receptors in the sino-atrial node and right atrium of bovine heart.
pubmed:affiliation
Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Canada.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't