N -methylaspartate-activated calcium channels in rat brain cortex slices. Effect of calcium channel blockers and of inhibitory and depressant substances
Identifieur interne : 001697 ( Main/Exploration ); précédent : 001696; suivant : 001698N -methylaspartate-activated calcium channels in rat brain cortex slices. Effect of calcium channel blockers and of inhibitory and depressant substances
Auteurs : N. Riveros [Chili] ; F. Orrego [Chili]Source :
- Neuroscience [ 0306-4522 ] ; 1986.
English descriptors
Abstract
Abstract: N-Methyl-dl-aspartate, l-glutamate, kainate and dl-homocysteate were found to increase the initial rate and the maximal uptake of 45Ca into the non-inulin space of rat brain cortex slices incubated in vitro. The N-methylaspartate-stimulated calcium uptake was blocked by cadmium and cobalt ions, but not by the organic calcium channel blocker nifedipine or by tetrodotoxin, both of which stimulated the N-methylaspartate-independent calcium influx, γ-Aminobutyrate increased the spontaneous calcium influx, and also reduced that stimulated by N-methylaspartate to the same level, as found with γ-aminobutyrate alone. Adenosine (1–100 μM), ethanol (0.1 M), pentobarbital (10–100 μM) and morphine (0.2 mM), were unable to inhibit the N-methylaspartate-activated calcium influx. Ethanol (0.1 M), had no effect on the glutamate- or kainate-activated calcium influx.These findings suggest that the excitatory amino acids, because of their neuronal depolarizing action in brain cortex, lead to the opening of voltage-sensitive calcium channels, which may be blocked by cadmium, but not by the organic calcium channel antagonist, nifedipine. The activation of calcium channels by the excitatory amino acid N-methylaspartate, was entirely unaffected by the depressants ethanol, pentobarbital or morphine, or by the endogenous inhibitory substance, adenosine, thus suggesting that their inhibitory or depressant effects occur through interference with a neuronal mechanism unrelated to the one studied here. γ-Aminobutyrate, on the other hand, considerably inhibited N-methylaspartate-induced calcium uptake, an effect interpreted as due to a γ-aminobutyrate-induced increase in chloride conductance, that “clamps” the membrane potential and does not allow further depolarization by N-methylaspartate.
Url:
DOI: 10.1016/0306-4522(86)90029-1
Affiliations:
Links toward previous steps (curation, corpus...)
- to stream Istex, to step Corpus: 000969
- to stream Istex, to step Curation: 000594
- to stream Istex, to step Checkpoint: 000E69
- to stream Main, to step Merge: 001757
- to stream Main, to step Curation: 001697
Le document en format XML
<record><TEI wicri:istexFullTextTei="biblStruct"><teiHeader><fileDesc><titleStmt><title xml:lang="en">N -methylaspartate-activated calcium channels in rat brain cortex slices. Effect of calcium channel blockers and of inhibitory and depressant substances</title><author><name sortKey="Riveros, N" sort="Riveros, N" uniqKey="Riveros N" first="N." last="Riveros">N. Riveros</name></author><author><name sortKey="Orrego, F" sort="Orrego, F" uniqKey="Orrego F" first="F." last="Orrego">F. Orrego</name></author></titleStmt><publicationStmt><idno type="wicri:source">ISTEX</idno><idno type="RBID">ISTEX:1883267B2D4E0F72CE32D0E220BCC686A39B1E99</idno><date when="1986" year="1986">1986</date><idno type="doi">10.1016/0306-4522(86)90029-1</idno><idno type="url">https://api.istex.fr/document/1883267B2D4E0F72CE32D0E220BCC686A39B1E99/fulltext/pdf</idno><idno type="wicri:Area/Istex/Corpus">000969</idno><idno type="wicri:explorRef" wicri:stream="Istex" wicri:step="Corpus" wicri:corpus="ISTEX">000969</idno><idno type="wicri:Area/Istex/Curation">000594</idno><idno type="wicri:Area/Istex/Checkpoint">000E69</idno><idno type="wicri:explorRef" wicri:stream="Istex" wicri:step="Checkpoint">000E69</idno><idno type="wicri:doubleKey">0306-4522:1986:Riveros N:n:methylaspartate:activated</idno><idno type="wicri:Area/Main/Merge">001757</idno><idno type="wicri:Area/Main/Curation">001697</idno><idno type="wicri:Area/Main/Exploration">001697</idno></publicationStmt><sourceDesc><biblStruct><analytic><title level="a" type="main" xml:lang="en">N -methylaspartate-activated calcium channels in rat brain cortex slices. Effect of calcium channel blockers and of inhibitory and depressant substances</title><author><name sortKey="Riveros, N" sort="Riveros, N" uniqKey="Riveros N" first="N." last="Riveros">N. Riveros</name><affiliation wicri:level="1"><country xml:lang="fr">Chili</country><wicri:regionArea>Department of Physiology and Biophysics, Faculty of Medicine, Universidad de Chile, Casilla 137-D, Santiago </wicri:regionArea><wicri:noRegion>Santiago </wicri:noRegion></affiliation></author><author><name sortKey="Orrego, F" sort="Orrego, F" uniqKey="Orrego F" first="F." last="Orrego">F. Orrego</name><affiliation wicri:level="1"><country xml:lang="fr">Chili</country><wicri:regionArea>Department of Physiology and Biophysics, Faculty of Medicine, Universidad de Chile, Casilla 137-D, Santiago </wicri:regionArea><wicri:noRegion>Santiago </wicri:noRegion></affiliation></author></analytic><monogr></monogr><series><title level="j">Neuroscience</title><title level="j" type="abbrev">NSC</title><idno type="ISSN">0306-4522</idno><imprint><publisher>ELSEVIER</publisher><date type="published" when="1986">1986</date><biblScope unit="volume">17</biblScope><biblScope unit="issue">3</biblScope><biblScope unit="page" from="541">541</biblScope><biblScope unit="page" to="546">546</biblScope></imprint><idno type="ISSN">0306-4522</idno></series><idno type="istex">1883267B2D4E0F72CE32D0E220BCC686A39B1E99</idno><idno type="DOI">10.1016/0306-4522(86)90029-1</idno><idno type="PII">0306-4522(86)90029-1</idno><idno type="ArticleID">86900291</idno></biblStruct></sourceDesc><seriesStmt><idno type="ISSN">0306-4522</idno></seriesStmt></fileDesc><profileDesc><textClass><keywords scheme="KwdEn" xml:lang="en"><term>GABA</term><term>NMA</term><term>NMDA</term><term>TTX</term></keywords></textClass><langUsage><language ident="en">en</language></langUsage></profileDesc></teiHeader><front><div type="abstract" xml:lang="en">Abstract: N-Methyl-dl-aspartate, l-glutamate, kainate and dl-homocysteate were found to increase the initial rate and the maximal uptake of 45Ca into the non-inulin space of rat brain cortex slices incubated in vitro. The N-methylaspartate-stimulated calcium uptake was blocked by cadmium and cobalt ions, but not by the organic calcium channel blocker nifedipine or by tetrodotoxin, both of which stimulated the N-methylaspartate-independent calcium influx, γ-Aminobutyrate increased the spontaneous calcium influx, and also reduced that stimulated by N-methylaspartate to the same level, as found with γ-aminobutyrate alone. Adenosine (1–100 μM), ethanol (0.1 M), pentobarbital (10–100 μM) and morphine (0.2 mM), were unable to inhibit the N-methylaspartate-activated calcium influx. Ethanol (0.1 M), had no effect on the glutamate- or kainate-activated calcium influx.These findings suggest that the excitatory amino acids, because of their neuronal depolarizing action in brain cortex, lead to the opening of voltage-sensitive calcium channels, which may be blocked by cadmium, but not by the organic calcium channel antagonist, nifedipine. The activation of calcium channels by the excitatory amino acid N-methylaspartate, was entirely unaffected by the depressants ethanol, pentobarbital or morphine, or by the endogenous inhibitory substance, adenosine, thus suggesting that their inhibitory or depressant effects occur through interference with a neuronal mechanism unrelated to the one studied here. γ-Aminobutyrate, on the other hand, considerably inhibited N-methylaspartate-induced calcium uptake, an effect interpreted as due to a γ-aminobutyrate-induced increase in chloride conductance, that “clamps” the membrane potential and does not allow further depolarization by N-methylaspartate.</div></front></TEI><affiliations><list><country><li>Chili</li></country></list><tree><country name="Chili"><noRegion><name sortKey="Riveros, N" sort="Riveros, N" uniqKey="Riveros N" first="N." last="Riveros">N. Riveros</name></noRegion><name sortKey="Orrego, F" sort="Orrego, F" uniqKey="Orrego F" first="F." last="Orrego">F. Orrego</name></country></tree></affiliations></record>Pour manipuler ce document sous Unix (Dilib)
EXPLOR_STEP=$WICRI_ROOT/Wicri/Terre/explor/CobaltMaghrebV1/Data/Main/Exploration
HfdSelect -h $EXPLOR_STEP/biblio.hfd -nk 001697 | SxmlIndent | more
Ou
HfdSelect -h $EXPLOR_AREA/Data/Main/Exploration/biblio.hfd -nk 001697 | SxmlIndent | more
Pour mettre un lien sur cette page dans le réseau Wicri
{{Explor lien
|wiki= Wicri/Terre
|area= CobaltMaghrebV1
|flux= Main
|étape= Exploration
|type= RBID
|clé= ISTEX:1883267B2D4E0F72CE32D0E220BCC686A39B1E99
|texte= N -methylaspartate-activated calcium channels in rat brain cortex slices. Effect of calcium channel blockers and of inhibitory and depressant substances
}}
| This area was generated with Dilib version V0.6.32. |  |