Characterization of GABA/sub A/ receptor-mediated /sup 36/chloride uptake in rat brain synaptoneurosomes

Journal Article · Mon Sep 07 00:00:00 EDT 1987 · Life Sci.; (United States)

DOI:https://doi.org/10.1016/0024-3205(87)90207-4· OSTI ID:6168944

Luu, M D; Morrow, A L; Paul, S M; Schwartz, R D

..gamma..-Aminobutyric acid (GABA) receptor-mediated /sup 36/chloride (/sup 36/Cl/sup -/) uptake was measured in synaptoneurosomes from rat brain. GABA and GABA agonists stimulated /sup 36/Cl/sup -/ uptake in a concentration-dependent manner with the following order of potency: Muscimol>GABA>piperidine-4-sulfonic acid (P4S)>4,5,6,7-tetrahydroisoxazolo-(5,4-c)pyridin-3-ol (THIP)=3-aminopropanesulfonic acid (3APS)>>taurine. Both P4S and 3APS behaved as partial agonists, while the GABA/sub B/ agonist, baclofen, was ineffective. The response to muscimol was inhibited by bicuculline and picrotoxin in a mixed competitive/non-competitive manner. Other inhibitors of GABA receptor-opened channels or non-neuronal anion channels such as penicillin, picrate, furosemide and disulfonic acid stilbenes also inhibited the response to muscimol. A regional variation in muscimol-stimulated /sup 36/Cl/sup -/ uptake was observed; the largest responses were observed in the cerebral cortex, cerebellum and hippocampus, moderate responses were obtained in the striatum and hypothalamus and the smallest response was observed in the pons-medulla. GABA receptor-mediated /sup 36/Cl/sup -/ uptake was also dependent on the anion present in the media. The muscinol response varied in media containing the following anions: Br/sup -/>Cl/sup -/greater than or equal toNO/sub 3//sup -/>I/sup -/greater than or equal toSCN/sup -/>>C/sub 3/H/sub 5/OO/sup -/greater than or equal toClO/sub 4//sup -/>F/sup -/, consistent with the relative anion permeability through GABA receptor-gated anion channels and the enhancement of convulsant binding to the GABA receptor-gated Cl/sup -/ channel. 43 references, 4 figures, 3 tables.

• Research Organization: National Institute of Mental Health, Bethesda, MD
• OSTI ID: 6168944
• Journal Information: Life Sci.; (United States), Journal Name: Life Sci.; (United States) Vol. 41:10; ISSN LIFSA
• Country of Publication: United States
• Language: English

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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINO ACIDS
AMINOBUTYRIC ACID
ANIMAL CELLS
ANIMALS
ANIONS
AUTONOMIC NERVOUS SYSTEM AGENTS
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CHLORINE ISOTOPES
DATA
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EXPERIMENTAL DATA
INFORMATION
IONS
ISOTOPES
KINETICS
LIGHT NUCLEI
MAMMALS
MEMBRANE PROTEINS
NERVE CELLS
NERVOUS SYSTEM
NEUROREGULATORS
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
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RADIONUCLIDE KINETICS
RATS
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RECEPTORS
RESPONSE MODIFYING FACTORS
RODENTS
SOMATIC CELLS
UPTAKE
VERTEBRATES
YEARS LIVING RADIOISOTOPES