Mutual Inhibition Kinetic Analysis of γ‐Aminobutyric Acid, Taurine, and β‐Alanine High‐Affinity Transport into Neurons and Astrocytes: Evidence for Similarity Between the Taurine and β‐Alanine Carriers in Both Cell Types
- 1 August 1986
- journal article
- research article
- Published by Wiley in Journal of Neurochemistry
- Vol. 47 (2), 426-432
- https://doi.org/10.1111/j.1471-4159.1986.tb04519.x
Abstract
The transport kinetics of gamma-aminobutyric acid (GABA), taurine, and beta-alanine in addition to the mutual inhibition patterns of these compounds were investigated in cultures of neurons and astrocytes derived from mouse cerebral cortex. A high-affinity uptake system for each amino acid was demonstrated both in neurons (Km GABA = 24.9 +/- 1.7 microM; Km Tau = 20.0 +/- 3.3 microM; Km beta-Ala = 73.0 +/- 3.6 microM) and astrocytes (Km GABA = 31.4 +/- 2.9 microM, Km Tau = 24.7 +/- 1.3 microM; Km beta-Ala = 70.8 +/- 3.6 microM). The maximal uptake rates (Vmax) determined were such that, in neurons, Vmax GABA greater than Vmax beta-Ala = Vmax Tau, whereas in astrocytes, Vmax beta-Ala greater than Vmax Tau = Vmax GABA. Taurine was found to inhibit beta-alanine uptake into neurons and astrocytes in a competitive manner, with Ki values of 217 microM in neurons and 24 microM in astrocytes. beta-Alanine was shown to inhibit taurine uptake in neurons and astrocytes, also in a competitive manner, with Ki values of 72 microM in neurons and 71 microM in astrocytes. However, beta-alanine was found to be a weak noncompetitive inhibitor of neuronal and astrocytic GABA uptake, whereas in reverse experiments, GABA displayed weak noncompetitive inhibition of neuronal and astrocytic uptake of beta-alanine. Likewise, taurine was a weak noncompetitive inhibitor of GABA uptake in neurons and similarly, GABA was a weak noncompetitive inhibitor of taurine uptake into neurons.(ABSTRACT TRUNCATED AT 250 WORDS)Keywords
This publication has 39 references indexed in Scilit:
- Ion dependency of uptake and release of GABA and (RS)‐nipecotic acid studied in cultured mouse brain cortex neuronsJournal of Neuroscience Research, 1983
- Beta-alanine uptake is not a marker for brain astroglia in cultureBrain Research, 1982
- Effect of Homo-?-Proline and Other Heterocyclic GAB A Analogues on GABA Uptake in Neurons and Astroglial Cells and on GABA Receptor BindingJournal of Neurochemistry, 1981
- β‐ Alanine, a Possible Neurotransmitter in the Visual System?Journal of Neurochemistry, 1981
- Changes in the Uptake of GABA and Taurine During Neuronal and Glial MaturationJournal of Neurochemistry, 1980
- CHARACTERIZATION OF TAURINE UPTAKE BY NEURONAL AND GLIAL CELLS IN CULTUREJournal of Neurochemistry, 1979
- Rat cortical neurons in cell culture: Culture methods, cell morphology, electrophysiology, and synapse formationBrain Research, 1978
- Action and uptake of neurotransmitters in cns tissue cultureReviews of physiology, biochemistry and pharmacology, 1978
- Is β-alanine an inhibitory neurotransmitter?General Pharmacology: The Vascular System, 1977
- A Modification of Davidon's Minimization Method to Accept Difference Approximations of DerivativesJournal of the ACM, 1967