Protection from local anesthetic-induced convulsions by gamma-aminobutyric acid.

The effects of gamma-aminobutyric acid (GABA) on the induction of convulsions by local anesthetics were investigated in mice and rats. Intraventricular administration of 0.8-1.6 mg GABA protected rats against convulsions induced by procaine, lidocaine, cocaine, and tetracaine in a dose-related manner. Intraperitoneal gamma-acetylenic GABA was also effective against procaine-induced convulsions in mice, but the metabolites of GABA, gamma-hydroxybutyrate, and gamma-butyrolactone were without effect. Intraventricular GABA, 1.6 mg, delayed the onset of convulsions induced by hydrazine, but had no influence on the incidence of convulsions induced by nicotine, pentylenetetrazol, picrotoxin, or strychnine. These results suggest that the GABA system may be involved in the mechanisms of local anesthetic-induced convulsions.