Effect of the 'antidementia drug' pantoyl-GABA on high affinity transport of choline and on the contents of choline and acetylcholine in rat brain.

1. Effect of pantoyl-gamma-aminobutyric acid (pantoyl-GABA) on high affinity transport of choline into synaptosomes and on the choline (Ch) and acetylcholine (ACh) concentrations of rat brain were studied. 2. Pantoyl-GABA was injected intraperitoneally four times at a dose of 500 mg kg-1 at intervals of 30 min. One hour after the last injection, rats were killed by decapitation for measurement of high affinity transport of Ch into synaptosomes or by microwave irradiation for the measurement of Ch and ACh concentrations. 3. Transport of Ch was increased into synaptosomes prepared from the cerebral cortex and hippocampus, but not into those from the striatum. 4. In the cerebral cortex and hippocampus, Ch concentration was increased and ACh concentration decreased. 5. Since treatments that enhance the activity of cholinergic neurones in vivo are reported to increase high affinity transport of Ch measured in vitro, the present results suggest that pantoyl-GABA may increase cholinergic activity in vivo. This action of the drug may be related to changes in the Ch and ACh concentrations.