Effects of glycine and other inhibitory amino acid neurotransmitters on strychnine convulsive threshold in mice.

The effects of glycine and other inhibitory amino acid neurotransmitters on strychnine convulsive threshold were studied in mice. The mean intravenous threshold dose for strychnine to produce its convulsive effects in briefly restrained mice was determined to be 1.386 +/- 0.035 mg/kg. The dose of strychnine produced 100% postconvulsive mortality in all the mice tested. Intraperitoneal administration of various doses (100-500 mg/kg) of glycine, beta-alanine and L-threonine, 15-20 minutes prior to strychnine infusion produced an increase of 13.92%, 25.73% and 17.15% respectively in strychnine convulsive threshold in mice. Diazepam, known to produce its anticonvulsant, sedative and muscle relaxant effects through its interaction either with central GABA or glycine receptors was found to be the most potent (48.39%) in increasing strychnine convulsive threshold. Taurine and Baclofen were found to be ineffective in raising strychnine convulsive threshold in mice. These observations favor the possible use of either glycine or beta-alanine in addition to diazepam in treating clinical cases of strychnine neurotoxicoses.