Document Detail


gamma-Hydroxybutyrate modulation of glutamate levels in the hippocampus: an in vivo and in vitro study.
MedLine Citation:
PMID:  11553667     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effect of gamma-hydroxybutyric acid on extracellular glutamate levels in the hippocampus was studied by microdialysis in freely moving rats and in isolated hippocampal synaptosomes. Intra-hippocampal (CA1) perfusion with gamma-hydroxybutyric acid (10 nM-1 mM) concentration-dependently influenced glutamate levels: gamma-hydroxybutyric acid (100 and 500 nM) increased glutamate levels; 100 and 300 microM concentrations were ineffective; whereas the highest 1 mM concentration reduced local glutamate levels. The stimulant effect of gamma-hydroxybutyric acid (100 nM) was suppressed by the locally co-perfused gamma-hydroxybutyric acid receptor antagonist NCS-382 (10 microM) but not by the GABA(B) receptor antagonist CGP-35348 (500 microM). Furthermore, the gamma-hydroxybutyric acid (1 mM)-induced reduction in CA1 glutamate levels was counteracted by NCS-382 (10 microM), and it was also reversed into an increase by CGP-35348. Given alone, neither NCS-382 nor CGP-35348 modified glutamate levels. In hippocampal synaptosomes, gamma-hydroxybutyric acid (50 and 100 nM) enhanced both the spontaneous and K(+)-evoked glutamate efflux, respectively, both effects being counteracted by NCS-382 (100 nM), but not by CGP-35348 (100 microM). These findings indicate that gamma-hydroxybutyric acid exerts a concentration-dependent regulation of hippocampal glutamate transmission via two opposing mechanisms, whereby a direct gamma-hydroxybutyric acid receptor mediated facilitation is observed at nanomolar gamma-hydroxybutyric acid concentrations, and an indirect GABA(B) receptor mediated inhibition predominates at millimolar concentrations.
Authors:
L Ferraro; S Tanganelli; W T O'Connor; W Francesconi; A Loche; G L Gessa; T Antonelli
Related Documents :
22085137 - Novel phenoxyalkylcarboxylic acid derivatives as hypolipidaemic agents.
18627167 - Synthesis of angiotensin i-converting enzyme (ace)-inhibitory peptides and gamma-aminob...
6834147 - Effects of maternal vitamin b-6 deficiency on specific regions of developing rat brain:...
9504847 - Distribution of glutamate-, glycine- and gaba-immunoreactive nerve terminals on dendrit...
4937787 - Multivalent repression and genetic depression of isoleucine-valine biosynthetic enzymes...
16417487 - Polyunsaturated fatty acids and neurotransmission in caenorhabditis elegans.
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of neurochemistry     Volume:  78     ISSN:  0022-3042     ISO Abbreviation:  J. Neurochem.     Publication Date:  2001 Sep 
Date Detail:
Created Date:  2001-09-12     Completed Date:  2001-10-25     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2985190R     Medline TA:  J Neurochem     Country:  United States    
Other Details:
Languages:  eng     Pagination:  929-39     Citation Subset:  IM    
Affiliation:
Department of Clinical and Experimental Medicine, Pharmacology Section, University of Ferrara, Ferrara, Italy.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Anesthetics, Intravenous / pharmacology*
Animals
Anticonvulsants / pharmacology
Benzocycloheptenes / pharmacology
Calcium / pharmacology
Consciousness / physiology
Extracellular Space / metabolism
GABA Antagonists / pharmacology
Glutamic Acid / metabolism*
Hippocampus / drug effects*,  metabolism*
Male
Microdialysis
Organophosphorus Compounds / pharmacology
Potassium / pharmacology
Rats
Rats, Sprague-Dawley
Sodium Oxybate / pharmacology*
Synaptic Transmission / drug effects,  physiology
Synaptosomes / drug effects,  metabolism
Tetrodotoxin / pharmacology
Chemical
Reg. No./Substance:
0/Anesthetics, Intravenous; 0/Anticonvulsants; 0/Benzocycloheptenes; 0/GABA Antagonists; 0/Organophosphorus Compounds; 123690-79-9/CGP 35348; 131733-92-1/NCS 382; 4368-28-9/Tetrodotoxin; 502-85-2/Sodium Oxybate; 56-86-0/Glutamic Acid; 7440-09-7/Potassium; 7440-70-2/Calcium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Strengths and weaknesses of traditional Chinese medicine and Western medicine in the eyes of some Ho...
Next Document:  Differences in survival-promoting effects and intracellular signaling properties of BDNF and IGF-1 i...