Linked Life Data

19666044

Source:http://linkedlifedata.com/resource/pubmed/id/19666044

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
20
pubmed:dateCreated
2009-10-5
pubmed:abstractText
gamma-Aminobutyric acid (GABA) is considered to be the most important inhibitory neurotransmitter in the central nervous system, including the retina. It has been shown that nitric oxide (NO) can influence the physiology of all retinal neuronal types, by mechanisms including modulation of GABA release. However, until now, there have been no data concerning the effects on endogenous GABA release of NO produced by cells in the intact retina. In the present study, we have investigated how NO production induced by drugs influences the release of endogenous GABA in cells of the intact retina of mature chicken. Retinas were exposed to different drugs that affect NO production, and GABA remaining in the tissue was detected by immunohistochemical procedures. A specific nNOS inhibitor (7-NI) reduced the number of GABA+amacrine cells and cells in the ganglion cell layer (GCL) by 33% and 41%, respectively. A GABA transporter inhibitor blocked this effect. L-arginine (100 microM), the precursor of NO, induced increases of 62% and 34% in the number of GABA+amacrine cells and GCL cells, respectively. A sodium (Na(+))-free solution, 7-NI and a PKG inhibitor prevented the effect of L-arginine (100 microM). However, a higher concentration of L-arginine (1mM) induced a 35% reduction in the number of GABA+cells by a Na(+)-dependent mechanism that was restricted to the GCL population. NMDA, which stimulates NO production, increased GABA release as indicated by 53% and 38% reductions in the number of GABA+amacrine cells and GCL cells, respectively. This effect was blocked by 7-NI only in GCL cells. We conclude that basal NO production and moderate NO production (possibly induced by L-arginine; 100 microM) inhibit basal GABA release from amacrine cells and GCL cells. However, NMDA or L-arginine (1mM) induce a NO-dependent increase in GABA release in GCL cells, possibly by stimulating higher NO production.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1878-5646
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
49
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2494-502
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Modulation of GABA release by nitric oxide in the chick retina: different effects of nitric oxide depending on the cell population.
pubmed:affiliation
Laboratório de Neurobiologia da Retina do Instituto de Biofísica Carlos Chagas Filho da UFRJ, Brazil.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't