The epileptogenic action of the taurine analogue guanidinoethane sulfonate may be caused by a blockade of GABA receptors
- 1 May 1990
- journal article
- research article
- Published by Wiley in Journal of Neuroscience Research
- Vol. 26 (1), 98-104
- https://doi.org/10.1002/jnr.490260112
Abstract
The aim of this paper is to clarify the mechanism through which the taurine analogue guanidinoethane sulfonate (GES) produces its epileptogenic effects. Experiments were performed in the rat hippocampus in vivo, using a brain dialysis probe also containing a recording electrode. Perfusion of 10 mM GES induced an enhancement of extracellular taurine levels probably as a result of forced efflux through the taurine uptake systems in a heteroexchange process. This taurine increase was highly reversible. GES also induced an increase of neuronal excitability and an impairment of recurrent inhibition as judged by the neuronal pattern discharge of evoked potentials. These results indicate the possible implication of GABA receptors in the epileptogenic effect of GES. Specific binding of [3H]‐GABA to P2 fractions was inhibited by both bicuculline methiodide (BMI) and GES with the same potency. Similar results were obtained using cerebral sections. Autoradiographic experiments confirm the binding results. GES and BMI completely displaced [3H]‐GABA binding. All these results suggest that the epileptogenic GES action is due to a direct antagonism on GABAA receptors.Keywords
This publication has 28 references indexed in Scilit:
- Higher susceptibility of taurine-deficient rats to seizures induced by 4-aminopyridineNeuropharmacology, 1987
- Pentylenetetrazol seizure threshold and extracellular levels of cortical amino acids in taurine‐deficient kittensActa Physiologica Scandinavica, 1987
- γ‐Aminobutyric Acid Greatly Increases the In Vivo Extracellular Taurine in the Rat HippocampusJournal of Neurochemistry, 1985
- Actions of guanidinoethane sulfonate on taurine concentration, retinal morphology and seizure threshold in the neonatal ratNeurochemistry International, 1985
- The anticonvulsive actions of two lipophilic taurine derivativesNeurochemistry International, 1985
- The Current Status of Taurine in EpilepsyClinical Neuropharmacology, 1983
- Modulatory Action of Taurine on the Release of GABA in Cerebellar Slices of the Guinea PigJournal of Neurochemistry, 1983
- High-affinity, Na+-independent, strychnine-sensitive binding sites for β-alanine in a synaptosome-enriched fraction of rat CNSGeneral Pharmacology: The Vascular System, 1977
- Antagonism by taurine of cobalt induced epilepsy in cat and mouseBrain Research, 1972
- Excitatory Synapses on Hippocampal Apical Dendrites Activated by Entorhinal StimulationActa Physiologica Scandinavica, 1966