Linked Life Data

1675670

Source:http://linkedlifedata.com/resource/pubmed/id/1675670

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1991-7-23
pubmed:abstractText
1. The physiological and pharmacological properties of excitatory amino acid (EAA)-induced responses were investigated in acutely isolated spiral ganglion cells of guinea pig by a conventional patch-clamp technique combined with a rapid drug application (Y-tube) method. 2. L-glutamate (Glu) and its agonists, quisqualate (QA) and kainate (KA), induced inward currents in a concentration-dependent manner at a holding potential (VH) of -70 mV. The values of half-maximal concentration (EC50) were 4.0 x 10(-4) M for Glu, 2.3 x 10(-5) M for QA, and 1.4 x 10(-4) for KA. The Hill coefficients were 0.96, 1.00, and 1.56 for Glu, QA, and KA, respectively. However, one of Glu agonists, N-methyl-D-aspartate (NMDA), and another excitatory amino acid, L-aspartate (Asp), did not induce any responses even in Mg2(+)-free external solution containing 10(-6) M glycine (Gly). 3. The current-voltage (I-V) relationships for the Glu-, QA-, and KA-induced responses were linear, and these reversal potentials were near 5 mV. 4. Kynurenic acid (Kyn), 6,7-dichloro-3-hydroxy-2-quinoxalinecarboxylic acid (diCl-HQC), and quinoxalinediones such as 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and 6,7-dinitro-quinoxaline-2,3-dione (DNQX) suppressed the Glu-, QA-, and KA-induced currents in a concentration-dependent manner. The inhibitory potency was in the order of DNQX = CNQX greater than diCl-HQC greater than Kyn. 5. CNQX antagonized the Glu-, QA-, and KA-induced currents without affecting the maximum responses showing no voltage-dependency, indicating the competitive inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-3077
pubmed:author
pubmed:issnType
Print
pubmed:volume
65
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
715-23
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Excitatory amino acid response in isolated spiral ganglion cells of guinea pig cochlea.
pubmed:affiliation
Department of Neurophysiology, Tohoku University School of Medicine, Sendai, Japan.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't