Antiseizure activity of gamma-acetylenic gamma-aminobutyric acid: a catalytic irreversible inhibitor of gamma-aminobutyric acid transaminase.

gamma-Acetylenic gamma-aminobutyric acid (gamma-acetylenic GABA) produces several-fold sustained elevations of brain GABA concentrations when administered intraperitoneally to mice. It protects mice against seizures induced by audiogenic stimuli, electroshock, thiosemicarbazide, isoniazid and strychnine. The duration and degree of audiogenic seizure protection appears to correlate with elevations in whole brain GABA levels. gamma-Acetylenic GABA does not protect against seizures induced by pentylenetetrazol or picrotoxin even at doses that increase brain GABA concentrations approximately 6-fold. This differential antiseizure activity suggests that the GABA system may play a role in some, but not all experimentally produced seizures.