Characterization of taurine binding, uptake, and release in the rat hypothalamus

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5681889

Hanretta, A T

The neurotransmitter criteria of specific receptors, inactivation, and release were experimentally examined for taurine in the hypothalamus. Specific membrane binding and synaptosomal uptake of taurine both displayed high affinity and low affinity systems. The neurotransmitter criterion of release was studied in superfused synaptosomes. Exposure of synaptosomes which had been preloaded with a concentration of (/sup 3/H)taurine in the high affinity uptake range (1.5 ..mu..M) to either 56 mM K/sup +/ or 100 ..mu..M veratridine evoked a Ca/sup 2 +/-independent release. Exposure of synaptosomes which had been preloaded with a concentration of (/sup 3/H)taurine in the low affinity uptake range (2 mM) to 56 mM K/sup +/ induced a Ca/sup 2 +/-independent release, whereas 100 /sup +/M veratridine did not, either in the presence or absence of Ca/sup 2 +/. Based on these results, as well as other observations, a model is proposed in which the high affinity uptake system is located on neuronal membranes and the low affinity uptake system is located on glial membranes. The mechanisms of binding, uptake, and release in relation to the cellular location of each are discussed. We conclude that the neurotransmitter criterion of activation by re-uptake is satisfied for taurine in the hypothalamus. However, the failure to demonstrate both a specific taurine receptor site and a Ca/sup 2 +/-dependent evoked release, necessitates that we conclude that taurine appears not to function as a hypothalamic neurotransmitter, at least not in the classical sense.

• Research Organization: Texas Tech Univ., Lubbock (USA)
• OSTI ID: 5681889
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
TAURINE
BIOCHEMICAL REACTION KINETICS
RECEPTORS
AFFINITY
BRAIN
CALCIUM COMPOUNDS
CATIONS
CELL MEMBRANES
MATHEMATICAL MODELS
POTASSIUM COMPOUNDS
RATS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
UPTAKE
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
AMINES
ANIMALS
BODY
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
CHARGED PARTICLES
IONS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
NERVOUS SYSTEM
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
PROTEINS
REACTION KINETICS
RODENTS
SULFONIC ACIDS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques