The anticonvulsant action of L-2,4-diaminobutyric acid.

The GABA uptake inhibitor, L-2,4-diaminobutyric acid (L-DABA) was examined for potential anticonvulsant activity in mice. Given intracerebroventricularly (i.c.v., 2 mumoles) L-DABA almost doubled the CD50 of picrotoxin and 3-mercaptopropionate (3-MP), a glutamate decarboxylase inhibitor--the convulsants being administered 15 min after the L-DABA. The anticonvulsant effect was not observed after 40 min. L-DABA given i.p (5 mmoles/kg) was also anticonvulsant against 3-MP but given i.p. or i.c.v. had no anticonvulsant action against strychnine. The D-isomer of DABA, less active as an inhibitor of GABA uptake, had no anticonvulsant activity against 3-MP and nor did three other inhibitors of GABA uptake, namely nipecotic acid, cis-1,3-aminocyclohexane carboxylic acid (ACHA) and beta-alanine. Possible mechanisms of the anticonvulsant action of L-DABA are discussed.