Regulation of sup 35 S-TBPS binding by bicuculline is region specific in rat brain

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Life Sciences; (United States)

OSTI ID:5699194

Peris, J; Shawley, A; Dawson, R; Abendschein, K H ^[1]

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1. Univ. of Florida Health Science Center, Gainesville (United States)

The allosteric regulation of specific {sup 35}S-TBPS binding to the convulsant site on the GABA{sub A} receptor/chloride (Cl{sup {minus}}) ionophore complex was studied in various brain regions in an attempt to characterize regional heterogeneity of the protein subunits forming the complex. Bicuculline methiodide (BIC), a GABA{sub A} antagonist, enhanced binding in cortex (CTX), substantia nigra (SN) and cerebellum (CBL), inhibited binding in inferior colliculus (IC) and did not affect binding in superior colliculus (SC). Similar results were found in CBL and IC using SR-95531, another GABA{sub A} antagonist. The levels of endogenous GABA in the different tissue samples could not account for the regional differences in binding. When the functional regulation of these receptors was measured using {sup 36}Cl{sup {minus}} uptake in microsomes, muscimol-stimulated uptake was completely blocked by BIC in CBL and IC but was not affected by BIC in SC. Additionally, picrotoxin completely blocked muscimol-stimulated uptake in CBL but had no effect in IC or SC. These findings provide a functional basis for regional heterogeneity of GABA{sub A} receptor.

• OSTI ID: 5699194
• Journal Information: Life Sciences; (United States), Journal Name: Life Sciences; (United States) Vol. 49:11; ISSN 0024-3205; ISSN LIFSA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
AMINOBUTYRIC ACID
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
CHEMICAL COMPOSITION
CHLORIDES
CHLORINE 36
CHLORINE COMPOUNDS
CHLORINE ISOTOPES
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
HALIDES
HALOGEN COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
MAMMALS
MEMBRANE PROTEINS
MICROSOMES
NERVOUS SYSTEM
NEUROREGULATORS
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RECEPTORS
RIBOSOMES
RODENTS
SULFUR 35
SULFUR ISOTOPES
SYMPATHOLYTICS
TRACER TECHNIQUES
VERTEBRATES
YEARS LIVING RADIOISOTOPES