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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2002-10-22
pubmed:abstractText
The neuromodulator adenosine mediates dark-adaptive changes in retinal photoreceptors through A(2a) receptors. In cold-blooded vertebrates, opsin mRNA expression is lower at night than during the day. In the present study, we tested whether adenosine could inhibit opsin mRNA expression in cultured rod cells and if endogenous adenosine acts to suppress opsin mRNA in the intact retina at night. Semi-quantitative in situ hybridization showed that treatment with 100 nm of the A(2a)/A(2b) agonist N(6)-[2-(3,5-dimethoxyphenyl)-2-(2-methylphenyl)-ethyl]adenosine (DPMA) reduced opsin mRNA 41% in cultured rod cells. The effect of DPMA was blocked by 10 microm of the A(2a) antagonist 8-(3-chlorostyryl)caffeine (CSC) but not by 10 microm of the A(2b) antagonist alloxazine. One micromolar adenosine alone had no effect on opsin mRNA. However, in the presence of the adenosine deaminase inhibitor erythro-9-(2-hydroxy-3-nonyl)adenine hydrochloride (EHNA), 1 microm adenosine reduced opsin mRNA 61%. EHNA alone reduced opsin mRNA by 26%. Consistent with an A(2a) receptor mechanism, 100 nm forskolin (adenylate cyclase agonist) decreased opsin mRNA 34%. Finally, northern blots showed that intravitreal injection of 10 microm CSC at night increased opsin I mRNA 38%. Thus, endogenous adenosine suppresses rod opsin I mRNA expression at night; in vitro results indicate this reduction occurs through A(2a)-like receptor binding and stimulation of adenylate cyclase activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/9-(2-hydroxy-3-nonyl)adenine, http://linkedlifedata.com/resource/pubmed/chemical/Adenine, http://linkedlifedata.com/resource/pubmed/chemical/Adenosine, http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Deaminase Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Adenylate Cyclase, http://linkedlifedata.com/resource/pubmed/chemical/CGS 24012, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Forskolin, http://linkedlifedata.com/resource/pubmed/chemical/Purinergic P1 Receptor Agonists, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger, http://linkedlifedata.com/resource/pubmed/chemical/Receptor, Adenosine A2A, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Purinergic P1, http://linkedlifedata.com/resource/pubmed/chemical/Rod Opsins
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-3042
pubmed:author
pubmed:issnType
Print
pubmed:volume
83
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
665-72
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:12390528-Adenine, pubmed-meshheading:12390528-Adenosine, pubmed-meshheading:12390528-Adenosine Deaminase Inhibitors, pubmed-meshheading:12390528-Adenylate Cyclase, pubmed-meshheading:12390528-Ambystoma, pubmed-meshheading:12390528-Animals, pubmed-meshheading:12390528-Cells, Cultured, pubmed-meshheading:12390528-Darkness, pubmed-meshheading:12390528-Enzyme Inhibitors, pubmed-meshheading:12390528-Forskolin, pubmed-meshheading:12390528-Gene Expression Regulation, pubmed-meshheading:12390528-Purinergic P1 Receptor Agonists, pubmed-meshheading:12390528-RNA, Messenger, pubmed-meshheading:12390528-Receptor, Adenosine A2A, pubmed-meshheading:12390528-Receptors, Purinergic P1, pubmed-meshheading:12390528-Retina, pubmed-meshheading:12390528-Retinal Rod Photoreceptor Cells, pubmed-meshheading:12390528-Rod Opsins
pubmed:year
2002
pubmed:articleTitle
Adenosine A(2a) receptor-mediated inhibition of rod opsin mRNA expression in tiger salamander.
pubmed:affiliation
Department of Neurosciences, UMDNJ-New Jersey Medical School, Newark, NJ, USA. alfinipe@umdnj.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.