Effects of volatile and intravenous anesthetics on the uptake of GABA, glutamate and dopamine by their transporters heterologously expressed in COS cells and in rat brain synaptosomes.
ABSTRACT Although the neurotransmitter uptake system is considered a possible target for the presynaptic action of anesthetic agents, observations are inconsistent concerning effects on the transporter and their clinical relevance. The present study examined the effects of volatile and intravenous anesthetics on the uptake of GABA, glutamate and dopamine in COS cells heterologously expressing the transporters for these neurotransmitters and in the rat brain synaptosomes. Halothane and isoflurane, but not thiamylal or thiopental, significantly inhibited uptake by COS cell systems of GABA, dopamine and glutamic acid in a concentration-dependent manner within clinically relevant ranges for anesthesia induced by these agents. Similarly, in synaptosomes halothane and isoflurane but not thiopental significantly suppressed the uptake of GABA and glutamic acid, respectively. These results do not support the hypothesis that volatile and intravenous anesthetics exert their action via specific inhibition of GABA uptake to enhance inhibitory GABAergic neuronal activity. Rather, they suggest that presynaptic uptake systems for various neurotransmitters including GABA may be the molecular targets for volatile anesthetic agents.
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ABSTRACT: Angelman syndrome is characterized by a partial deficit of paired autosomal chromosome 15, which contains a subunit of the GABA (Gamma-Amino Butyric Acid) receptor. Many drugs that act on the CNS (Central Nerve System) during anesthesia are believed to exert their effects via the GABA receptors. We describe the anesthesia of a 7 year-old female patient with Angelman syndrome who underwent surgery for dental caries. The basic factors that needed to be considered when administering anesthesia to this patient were epilepsy, significant dominance of the vagal tone, craniofacial abnormalities and peripheral muscular atrophy. Inhalational anesthetics (sevoflurane) were employed for this patient. The patient had an uneventful peri-operative period and was discharged home on the same day of the operation.Korean journal of anesthesiology 02/2010; 58(2):207-10.