Thiopental inhibition of γ-aminobutyrate transaminase in rat brain synaptosomes

A hypothetical model on the mechanism of anesthesia

An hypothesis on the mechanism of action of general anesthetic agents is proposed. It is based on a potentiation of chloride influx due to the action of anesthetic agents on the GABA-receptor complex at the lipid-protein interface. This hypothesis accommodates various observations such as lipid solubility of anesthetic molecules, their lack of stringent structural requirement, pressure reversal of anesthetic action, and other neurochemical and neuropharmacological data.

Induced enzyme release from synaptosomes by halothane

GABA-transaminase has been found to be released from rat brain synaptosomes by halothane in a dose-related manner. The releases of both GABA-transaminase and succinic semialdehyde dehydrogenase were increased with time. The release of other enzymes (creatine kinase, glutamate decarboxylase, aspartate transaminase, lactate dehydrogenase, and malate dehydrogenase) was less in magnitude and not related to the duration of incubation. Such observations suggested a specific event in the halothane-induced release of GABA-catabolizing enzymes. A suggestion linking mode of anesthetic action to a mitochondrial effect of volatile anesthetics was made.