Nafamostat enhances IBMX and secretin-stimulated water and bicarbonate secretion in the isolated, blood-perfused dog pancreas.

1. The effect of nafamostat mesilate, a synthetic protease inhibitor, on pancreatic exocrine secretion was investigated in isolated, blood-perfused dog pancreas. 2. Intra-arterial injections of nafamostat (2-10 mumol) dose-dependently enhanced water and bicarbonate secretion stimulated by 3-isobutyl-1-methylxanthine (IBMX) or secretin, although nafamostat alone did not affect the basal secretion. 3. In the nafamostat-enhanced pancreatic juice, bicarbonate concentrations were increased dose-dependently as compared with the control, while protein concentrations were not significantly changed. 4. These results indicate that nafamostat enhances IBMX and secretin-stimulated water and bicarbonate secretion, which may be mediated through cAMP activation.