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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1
|
| pubmed:dateCreated |
1998-2-17
|
| pubmed:abstractText |
A recently introduced technique of [gamma-35S]GTP autoradiography was used to localize and characterize muscarinic receptor-dependent activation of G-proteins in tissue sections of the chick optic tectum, a brain region with relatively high expression of G-protein-coupled receptors for the neurotransmitter acetylcholine. Within the highly stratified tectal structure, the bulk of muscarinic receptor-mediated [gamma-35S]GTP signal was localized to the stratum griseum et fibrosum superficiale with considerably lower binding responses in other tectal layers. Quantitative comparison of [gamma-35S]GTP binding responses in tectal sections and membranes revealed a close match between the two tissue preparations for the response elicited by the cholinergic agonist carbachol, its dose-dependent reversal with the non-selective muscarinic antagonist atropine, its approximately 100-fold sensitivity towards blockade with M1-type (pirenzepine) over M2-type (gallamine) muscarinic antagonists, as well as absolute requirement for micromolar concentrations of GDP (EC50 approximately 10 microM) for the receptor-mediated [gamma-35S]GTP response. The pharmacological profile is consistent with that of cm4, a recently cloned chicken homolog of the mammalian m4 muscarinic acetylcholine receptor. Moreover, the strict GDP-dependence of the binding response suggest activation of Gi/o, the inhibitory class of G-proteins. These data provide the first functional characterization of the chick tectal muscarinic receptors. A close match between [gamma-35S]GTP responses in membranes and tissue sections strongly suggest that [gamma-35S]GTP autoradiography offers great potential for studies on G-protein-mediated signaling, with particular use within anatomically restricted regions that are not readily approached with more conventional techniques. It is anticipated that [gamma-35S]GTP autoradiography should greatly facilitate studies on signaling capacity of an individual receptor subtype whilst in its native cellular environment.
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| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Carbachol,
http://linkedlifedata.com/resource/pubmed/chemical/GTP-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Guanosine Diphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Guanosine Triphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Muscarinic Agonists,
http://linkedlifedata.com/resource/pubmed/chemical/Muscarinic Antagonists,
http://linkedlifedata.com/resource/pubmed/chemical/Pirenzepine,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Muscarinic,
http://linkedlifedata.com/resource/pubmed/chemical/Sulfur Radioisotopes
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Sep
|
| pubmed:issn |
0006-8993
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
19
|
| pubmed:volume |
769
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
21-8
|
| pubmed:dateRevised |
2007-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:9374269-Animals,
pubmed-meshheading:9374269-Animals, Newborn,
pubmed-meshheading:9374269-Autoradiography,
pubmed-meshheading:9374269-Carbachol,
pubmed-meshheading:9374269-Chickens,
pubmed-meshheading:9374269-Dose-Response Relationship, Drug,
pubmed-meshheading:9374269-GTP-Binding Proteins,
pubmed-meshheading:9374269-Guanosine Diphosphate,
pubmed-meshheading:9374269-Guanosine Triphosphate,
pubmed-meshheading:9374269-Male,
pubmed-meshheading:9374269-Muscarinic Agonists,
pubmed-meshheading:9374269-Muscarinic Antagonists,
pubmed-meshheading:9374269-Pirenzepine,
pubmed-meshheading:9374269-Receptors, Muscarinic,
pubmed-meshheading:9374269-Sulfur Radioisotopes,
pubmed-meshheading:9374269-Superior Colliculi,
pubmed-meshheading:9374269-Time Factors,
pubmed-meshheading:9374269-Tissue Distribution
|
| pubmed:year |
1997
|
| pubmed:articleTitle |
[Gamma-35S]GTP autoradiography allows region-specific detection of muscarinic receptor-dependent G-protein activation in the chick optic tectum.
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| pubmed:affiliation |
Department of Physiology, University of Kuopio, Finland.
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| pubmed:publicationType |
Journal Article
|