The amplification of the anticonvulsant effect of vinyl GABA (4-aminohexenoic acid) by esters of glycine.

The synergistic amplification of the anticonvulsant effects of direct and indirect GABA agonists by glycine has previously been demonstrated. We show in the present report that the anticonvulsant effect of vinyl GABA, a GABA-T (4-aminobutyrate: 2-oxoglutarate aminotransferase) inhibitor with antiepileptic efficacy, can be amplified by esters of glycine. Among the compounds studied glycine tert. butylester was the most promising. It was effective at a lower dose and had a considerably longer duration of action than glycine. From the observed glycine and glycine tert. butylester levels it is evident that glycine tert. butylester is rapidly hydrolysed within brain and other tissues. It is therefore a pro-drug of glycine, capable of enhancing central glycinergic activity.