Transintestinal absorption of gamma-aminobutyric acid (GABA) via a pH-dependent mechanism is demonstrated in the human intestinal epithelial cell line Caco-2. Experiments with BCECF [2′,7′,-bis(2-carboxyethyl)-5(6)-carboxyfluorescein]-loaded Caco-2 cells show that GABA transport across the apical membrane is coupled to proton flux into the cell. A series of GABA analogues were tested for their abilities: (a) inhibit pH-dependent…
