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Glutamate agonists and [3H]GABA release from rat hippocampal slices: involvement of metabotropic glutamate receptors in the quisqualate-evoked release.
Neurochem Res. 1994 Jun; 19(6):729-34.NR

Abstract

The effects of glutamate agonists and their selective antagonists on the Ca(2+)-dependent and independent releases of [3H]GABA from rat coronal hippocampal slices were studied in a superfusion system. The Ca(2+)-dependent release evoked by glutamate, kainate and N-methyl-D-aspartate (NMDA) gradually declined with time despite the continuous presence of the agonists. Quisqualate (QA) caused a sustained release which exhibited no tendency to decline within the 20-min period of stimulation. This release was enhanced in Ca(2+)-free medium. The release evoked by QA in Ca(2+)-containing medium was significantly inhibited by (+)-5-methyl-10,11-dihydro-5H-dibenzo(a,d)cyclohept-5,10-imine hydrogen maleate (MK-801) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), showing that QA activates NMDA receptors directly or indirectly through (RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors. The inhibition of MK-801 was slightly diminished and that of CNQX totally abolished in Ca(2+)-free medium. Verapamil inhibited the QA-activated release in both Ca(2+)-containing and Ca(2+)-free media. The effect of QA but not that of AMPA was blocked in Ca(2+)-free medium by L(+)-2-amino-3-phosphonopropionate (L-AP3), a selective antagonist of the metabotropic glutamate receptor. It is suggested that the sustained release of GABA is also mediated partly by activation of metabotropic receptors and mobilization of Ca2+ form intracellular stores.

Authors+Show Affiliations

Department of Biomedical Sciences, University of Tampere, Finland.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

7915017

Citation

Janáky, R, et al. "Glutamate Agonists and [3H]GABA Release From Rat Hippocampal Slices: Involvement of Metabotropic Glutamate Receptors in the Quisqualate-evoked Release." Neurochemical Research, vol. 19, no. 6, 1994, pp. 729-34.
Janáky R, Varga V, Saransaari P, et al. Glutamate agonists and [3H]GABA release from rat hippocampal slices: involvement of metabotropic glutamate receptors in the quisqualate-evoked release. Neurochem Res. 1994;19(6):729-34.
Janáky, R., Varga, V., Saransaari, P., & Oja, S. S. (1994). Glutamate agonists and [3H]GABA release from rat hippocampal slices: involvement of metabotropic glutamate receptors in the quisqualate-evoked release. Neurochemical Research, 19(6), 729-34.
Janáky R, et al. Glutamate Agonists and [3H]GABA Release From Rat Hippocampal Slices: Involvement of Metabotropic Glutamate Receptors in the Quisqualate-evoked Release. Neurochem Res. 1994;19(6):729-34. PubMed PMID: 7915017.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Glutamate agonists and [3H]GABA release from rat hippocampal slices: involvement of metabotropic glutamate receptors in the quisqualate-evoked release. AU - Janáky,R, AU - Varga,V, AU - Saransaari,P, AU - Oja,S S, PY - 1994/6/1/pubmed PY - 1994/6/1/medline PY - 1994/6/1/entrez SP - 729 EP - 34 JF - Neurochemical research JO - Neurochem Res VL - 19 IS - 6 N2 - The effects of glutamate agonists and their selective antagonists on the Ca(2+)-dependent and independent releases of [3H]GABA from rat coronal hippocampal slices were studied in a superfusion system. The Ca(2+)-dependent release evoked by glutamate, kainate and N-methyl-D-aspartate (NMDA) gradually declined with time despite the continuous presence of the agonists. Quisqualate (QA) caused a sustained release which exhibited no tendency to decline within the 20-min period of stimulation. This release was enhanced in Ca(2+)-free medium. The release evoked by QA in Ca(2+)-containing medium was significantly inhibited by (+)-5-methyl-10,11-dihydro-5H-dibenzo(a,d)cyclohept-5,10-imine hydrogen maleate (MK-801) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), showing that QA activates NMDA receptors directly or indirectly through (RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors. The inhibition of MK-801 was slightly diminished and that of CNQX totally abolished in Ca(2+)-free medium. Verapamil inhibited the QA-activated release in both Ca(2+)-containing and Ca(2+)-free media. The effect of QA but not that of AMPA was blocked in Ca(2+)-free medium by L(+)-2-amino-3-phosphonopropionate (L-AP3), a selective antagonist of the metabotropic glutamate receptor. It is suggested that the sustained release of GABA is also mediated partly by activation of metabotropic receptors and mobilization of Ca2+ form intracellular stores. SN - 0364-3190 UR - https://www.unboundmedicine.com/medline/citation/7915017/Glutamate_agonists_and_[3H]GABA_release_from_rat_hippocampal_slices:_involvement_of_metabotropic_glutamate_receptors_in_the_quisqualate_evoked_release_ DB - PRIME DP - Unbound Medicine ER -