Competitive Inhibition of γ‐Aminobutyric Acid Synaptosomal Uptake by 4‐(4′‐Azidobenzoimidylamino)butanoic Acid

Abstract

4-(4''-Azidobenzoimidylamino)butanoic acid (ABBA) is a potent inhibitor of rat brain synaptosomal [3H]GABA uptake. K1 [inhibitor constant] values were calculated to be 8 and 16 .mu.M with respect to the high-affinity and the low-affinity uptake processes. These values are of the same order as those reported for nipecotic acid and guvacine, which until now have been the most potent uptake inhibitors available. Since ABBA contains a phenyl group, it might be capable of penetrating the blood-brain barrier, thus becoming a useful GABA mimetic.