el-aminobutyric acid (GABA) mediated transmembrane chloride flux with membrane vesicles from rat brain measured by quench flow technique: kinetic homogeneity of ion flux and receptor desensitization

Journal Article · Mon Jul 27 04:00:00 EDT 1987 · Life Sci.; (United States)

DOI:https://doi.org/10.1016/0024-3205(87)90219-0· OSTI ID:6157370

Cash, D J; Subbarao, K

Transmembrane chloride flux mediated by the GABA/sub A/ receptor and the desensitization of the receptor were followed using quench flow technique with TWCl and a membrane preparation from rat cerebral cortex. Measurements in short times allowed these two processes to be resolved. In general the ion-flux activity was desensitized in two phases. A fast phase took place in circa 200 ms (100 M GABA) followed by a slower phase in several seconds. A minority of the membrane preparations did not display the fast phase. It is desirable to be able to separate these two phases of desensitization to facilitate analysis of the responses of the receptor. A short preincubation with GABA removed the fast phase from a subsequent measurement. In the absence of the fast phase the whole ion-flux equilibrium was seen as a single phase. The measurements presented covering a time range of 0.01 seconds to 10 seconds show a single phase of ion flux which can be described by a first order ion influx process and a single first order desensitization process with a halt time of circa 1 s (100 M GABA). The results imply a single population of vesicles containing a single population of GABA receptor (remaining active) with a single phase of desensitization. An understanding of this homogeneity, and how to ensure it, gives a basis for quantitatively testing the effects of drugs on these responses. Ion flux measurements with quench flow technique are a suitable tool for investigation of the mechanism of action of neurotransmitter receptors from brain. 37 references, 3 figures.

• Research Organization: Univ. of Missouri-Columbia, St. Louis
• OSTI ID: 6157370
• Journal Information: Life Sci.; (United States), Journal Name: Life Sci.; (United States) Vol. 41:4; 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
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CELL MEMBRANES
CENTRAL NERVOUS SYSTEM
CHLORIDES
CHLORINE 36
CHLORINE COMPOUNDS
CHLORINE ISOTOPES
DATA
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
INFORMATION
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
MAMMALS
MEMBRANE TRANSPORT
MEMBRANES
NERVOUS SYSTEM
NEUROREGULATORS
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RADIOISOTOPES
RATS
REACTION KINETICS
RECEPTORS
RODENTS
TRACER TECHNIQUES
VERTEBRATES
YEARS LIVING RADIOISOTOPES