Antagonism of mercaptopropionic acid (MPA) induced convulsions, reflecting a GABAergic mechanism, was observed in a series of l-aryl-3-(aminoalkylidene) oxindoles. Optimal MPA antagonism was associated with 3-ha10, 3-alkyl, and/or 4-alkoxy substituents in the pendant aryl ring and with (dimethylamino) methylene, 1-(dimethylamino)-ethylidene and N-methyl-2- pyrrolidinylidene side chains. The precise mechanism of action of these agents is unclear ...
