Linked Life Data

9580597

Source:http://linkedlifedata.com/resource/pubmed/id/9580597

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-6-8
pubmed:abstractText
Cannabinoid receptors are members of the superfamily of G protein-coupled receptors. Their activation has previously been shown to stimulate guanosine 5'-O-(3-[35S]thio)-triphosphate ([35S]GTP gamma S) binding in a range of brain regions using both membrane preparations and autoradiography. This study evaluates the activities of structurally diverse cannabinoid receptor ligands in the GTP gamma S binding assay, comparing the relationship between receptor binding and activation and also examining efficacy differences between compounds. Using rat cerebellar membrane preparations, the effects of GDP concentration on GTP gamma S binding and the activities of a range of cannabinoid receptor ligands, including the CB1 selective antagonist SR141716A, were investigated. GDP concentration was found to have differing effects on cannabinoid-stimulated [35S]GTP gamma S binding depending on the nature of the agonist used. The stimulation produced by high efficacy compounds, such as CP 55,940 and WIN 55212-2, was increased by raising the GDP concentration, but that of a low efficacy agonist, (-)-delta-tetrahydrocannabinol, was decreased. Of the cannabinoid compounds tested, a wide range of potencies (EC50) and levels of maximal stimulation (Emax) were observed. These ranged from CP 55,244 (Emax of 165, 148-183%, and an EC50 of 0.47, 0.22-0.96, nM) through (-)-delta-tetrahydrocannabinol, cannabinol and anandamide, which produced no concentration-dependent stimulation of [35S]GTP gamma S binding under the same conditions. SR141716A competitively antagonized all the agonists against which it was tested, providing equilibrium dissociation constants (Kd values) in the sub-nanomolar range (0.06-0.40 nM), implicating a CB1 receptor mediated response. These results provide a more detailed characterization of the cannabinoid-stimulated [35S]GTP gamma S binding assay than has previously been reported.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
285
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
553-60
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Evaluation of cannabinoid receptor agonists and antagonists using the guanosine-5'-O-(3-[35S]thio)-triphosphate binding assay in rat cerebellar membranes.
pubmed:affiliation
Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't