The protective effect of 2-(4-chlorobenzoylamino)-3-[2(1H)-quinolinon-4-yl]-propionic acid (rebamipide) on gastric mucosa is well established. Here we demonstrate that rebamipide acts on pancreatic acinar cells to generate oscillations of intracellular Ca2+ concentration ([Ca2+](i)) through the activation of cholecystokinin subtype 1 (CCK1) receptors. At concentrations higher than 5 μM, rebamipide induced [Ca2+](i) oscillations in individual fura-2-loaded pancreatic acinar cells. The frequency of oscillations increased with increasing concentrations of rebamipide, while the latency between stimulation of cells and initiation of [Ca2+](i) oscillations decreased with increasing concentration. The [Ca2+](i) oscillations evoked by rebamipide were inhibited by the CCK1 receptor antagonist L-364,718 but not by atropine or the CCK2 receptor antagonist L-365,260 indicating that rebamipide is a nonpeptide CCK1 receptor agonist. Copyright (C) 2000 Elsevier Science B.V.
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