Linked Life Data

11755903

Source:http://linkedlifedata.com/resource/pubmed/id/11755903

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-12-28
pubmed:abstractText
The mechanism of control of GAD expression by GABA and excitatory amino acids (EAAs) was studied in chick and rat retina cultures using immunohistochemical and PAGE-immunoblot detection of the enzyme, as well as by measuring enzyme activity. Aggregate cultures were prepared with retina cells obtained from chick embryos at embryonic days 8-9 (E8-E9). Organotypical cultures were also prepared with retinas from E14 chick embryos, post-hatched chicken and P21 rats. GABA (1-20 mM) fully prevented GAD expression in aggregate and organotypical cultures from chick embryo retinas. A substantial, but not complete, reduction of GAD was also observed in organotypical cultures of post-hatched chicken and P21 rats, in which both forms of the enzyme (GAD65 and 67) were affected. The GABA effect was not mimicked by THIP (100 microM), baclofen (100 microM) or CACA (300 microM), agonists of GABAa, b and c receptors, respectively. NNC-711, a potent inhibitor of GABA transporters, reduced by 50% the inhibition of GAD activity promoted by GABA. Aggregates exposed to GABA and treated with glutamate (5 mM) or kainate (100 microM) displayed an intense GAD-like immunoreactivity in many cell bodies, but not in neurite regions. Immunoblot analysis revealed that the increase in GAD-like immunoreactivity by EAA corresponded to a 67-kDa protein. However, GAD activity was not detected. Treatment of aggregates or retina homogenates with SNAP, a NO producing agent (but not its oxidized form), reduced GAD activity by more than 60% indicating that the lack of enzyme activity in GAD-like immunoreactive cells, could be due to NO production by EAA stimulation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/4,5,6,7-tetrahydroisoxazolo(5,4-c)py..., http://linkedlifedata.com/resource/pubmed/chemical/Baclofen, http://linkedlifedata.com/resource/pubmed/chemical/Cytarabine, http://linkedlifedata.com/resource/pubmed/chemical/Excitatory Amino Acid Agonists, http://linkedlifedata.com/resource/pubmed/chemical/GABA Agonists, http://linkedlifedata.com/resource/pubmed/chemical/Glutamate Decarboxylase, http://linkedlifedata.com/resource/pubmed/chemical/Glutamic Acid, http://linkedlifedata.com/resource/pubmed/chemical/Isoxazoles, http://linkedlifedata.com/resource/pubmed/chemical/Kainic Acid, http://linkedlifedata.com/resource/pubmed/chemical/N(4)-chloroacetylcytosine..., http://linkedlifedata.com/resource/pubmed/chemical/Nitric Oxide, http://linkedlifedata.com/resource/pubmed/chemical/gamma-Aminobutyric Acid
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-8993
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
925
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
89-99
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Opposite roles of GABA and excitatory amino acids on the control of GAD expression in cultured retina cells.
pubmed:affiliation
Departamento de Farmacologia e Psicobiologia, Instituto de Biologia Roberto Alcântara Gomes, Uerj, Rio de Janeiro, Brazil.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't