title: Interrelationships between ornithine, glutamate and GABA-I. Feed-back inhibition of ornithine aminotransferase by elevated brain GABA levels.
abstract: In this work new methods for the determination of ornithine (Orn) and l-ornithine:2-oxoacid aminotransferase (OAT) activity are described. These methods were used to demonstrate linear interrelationships between brain GABA and Orn concentrations. Brain GABA levels were modulated by administration of vigabatrin (4-aminohex-5-enoic acid), a specific inactivator of GABA-T, which is not an inhibitor of OAT. The results suggest feed-back inhibition of OAT by GABA, a mechanism which is compatible with the assumption that Orn may serve in certain neurons as a precursor of glutamate and GABA.
authors.affiliation: Merrell Dow Research Institute, 16, rue d'Ankara, 67084 Strasbourg-Cedex, France.
authors.forename: N
authors.initials: N
authors.lastname: Seiler
authors.forename: H
authors.initials: H
authors.lastname: Spraggs
authors.forename: G
authors.initials: G
authors.lastname: Daune