The Anticonvulsant Properties of Isonicotinic Acid Hydrazide and Associated Changes in γ-Aminobutyric Acid Metabolism
The administration of isonicotinic acid hydrazide and pyridoxine to chicks prior to their being exposed to oxygen at high pressure brought about a delay in the onset of the hyperbaric-oxygen-induced seizures in the birds. The hydrazide was the active anticonvulsant component of the drug mixture but pyridoxine was necessary to prevent seizures induced by the hydrazide itself shortly after its administration. The anticonvulsant action of the drug mixture developed relatively slowly but lasted for several hours and correlated well with concomitant changes in the concentration of γ-aminobutyric acid (GABA) in the brain. No similar correlation was observed between the anticonvulsant action and the activity of either glutamic acid decarboxylase or GABA-α-oxoglutarate aminotransferase.