Background and Aims: Alcoholic beverages stimulate gastric acid secretion and increase appetite. Although ingested ethanol itself stimulates pancreatic secretion (Pancreas 30: e22, 2005), alcoholic beverages contain several congeners. N-methyltyramine (NMT) was isolated from beer as a factor to stimulate gastric acid secretion (Alcohol & Alcohol 34:161, 1999). In the present study, we examined whether NMT stimulated pancreatic secretion in conscious rats. Methods: Male Wistar rats (330g) were prepared with cannulae for draining bile and pancreatic juice separately, with two duodenal cannulae, with a gastric cannula, and with an external jugular vein cannula. The rats were placed in modified Bollman-type restraint cages. After the 4-day recovery period, the experiments were conducted in unanesthetized rats. Different concentrations of NMT solutions (5, 25, and 50 micro-g/kg/3ml/3min) were infused into the stomach. To examine the mechanism, the effects of proton pump inhibitor (PPI, 5 micromol/kg, intraduodenally), CCK-BR antagonist (YM022, 15 mg/kg, intravenously(iv)), CCK-AR antagonist (CR1505, 0.1 mg/kg/h, iv) and atropine (100 mg/kg/h, iv) were administered prior to the NMT (25 micro-g/kg) infusion, because a submaximal stimulation was yielded by this dose of NMT. The effect of intravenouis infusion of NMT (2.5 micro-g/rat) was determined. Moreover, dispersed acini were prepared and the effect of different concentration of NMT on amylase release were determined. Results: Intragastric administration of NMT significantly increased pancreatic exocrine secretion in a dose dependent manner. Atropine abolished the stimulatory effect of NMT, but others did not. Intravenous infusion of NMT did not affect pancreatic secretion, and NMT did not stimulate amylase release in vitro. Conclusions: NMT stimulates pancreatic secretion via cholinergic gastro-pancreatic reflex. NMT content in beer was 2 mg/L, so that if 50 kg body weight man consumes a bottle of beer, 25 micro-g/kg NMT will be ingested. Therefore, the stimulatory effect of beer on pancreatic secretion was produced by not only ethanol but also a congener, NMT.