Rebamipide and mosapride enhance pilocarpine-induced salivation

During esophageal acid clearance, salivation plays an important role in defending the esophageal mucosa. Mosapride, an agent used in chronic, long-term therapy of gastro-esophageal reflux disease (GERD) was regarded as mediating its efficacy through prokinetic properties. Rebamipide is also widely used as an anti-gastritis and anti-ulcer agent in GERD patients with chronic gastritis. The aim of this study is to investigate the effects of rebamipide, mosapride, and risperidone on the salivation induced by pilocarpine.

The experiments were conducted on 4-week male SD rats (120-150g). The salivation was induced by intraperitoneally administrated pilocarpine and saliva was collected using preweighted small cotton balls inserted into the animal's mouth every 30 min for 180 min. Thirteen minutes before intraperitoneal administration of pilocarpine, rebamipide, mosapride, and risperidone were administered intraduodenally. Control rats were conducted by intraperitoneal administration of saline and intraduodenal administration of 0.5% methylcellulose solution.

The saliva weight at 0-30 min was significantly (p<0.01) increased after administration of pilocarpine, compared to control rats. An additional administration of mosapride and rebamipide increased the saliva weight at 0-30 min. The total volume of saliva for 150 min after administration of pilocarpine was the highest after preadministration of rebamipide, followed by mosapride, and risperidone.

Increase in salivation produced by i.p. pilocarpine was enhanced by preadministration of rebamipide and mosapride.