Neuronal and non-neuronal GABA transporters as targets for antiepileptic drugs.
Epileptic seizure activity is associated with an imbalance between excitatory and inhibitory synaptic activities. The latter is mediated by GABA, and several currently used antiepileptic drugs target entities of the GABAergic synapse such as the receptors or the inactivation mechanism consisting of transmembrane transport and enzymatic degradation. The development of tiagabine selectively inhibiting the GABA transporter GAT1 constitutes a proof of concept that the GABA transporters are interesting drug targets in the context of antiepileptic drugs. The review provides a detailed analysis of the role of such transporters pointing in particular to an interesting role of the transporters located extrasynaptically. It is suggested that the betaine-GABA transporter BGT1 should receive particular interest in this context as the GABA analogue EF 1502 (N-[4,4-bis(3-methyl-2-thienyl)-3-butenyl]-4-(methylamino)-4,5,6,7-tetrahydrobenzo[d]isoxazol-3-ol) has been shown to possess a novel anticonvulsant profile in animal models of epilepsy, involving the ability to inhibit GABA transport mediated by GAT1 and BGT1 at the same time.
Madsen
Karsten K
KK
Department of Pharmacology and Pharmacotherapy, Faculty of Pharmaceutical Sciences, University of Copenhagen, Copenhagen, Denmark.
White
H Steve
HS
Schousboe
Arne
A
D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology* / Q000627:therapeutic use*; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D016503:Drug Delivery Systems / Q000379:methods*; D004827:Epilepsy / Q000188:drug therapy*; D050485:GABA Plasma Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D058805:GABA Uptake Inhibitors; D006801:Humans; D008959:Models, Neurological; D015394:Molecular Structure; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D014179:Neurotransmitter Uptake Inhibitors / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism / Q000502:physiology
D000927:Anticonvulsants; D050485:GABA Plasma Membrane Transport Proteins; D058805:GABA Uptake Inhibitors; D014179:Neurotransmitter Uptake Inhibitors; D005680:gamma-Aminobutyric Acid