The amiloride sensitive Na+/H+ antiport in guinea pig pancreatic acini. Characterization and stimulation by caerulein

Amiloride and analogs decrease the initial rate of 22Na+ uptake by dispersed acini from guinea pig pancreas in a dose-dependent manner. The initial rate of amiloride-sensitive 22Na+ uptake depends on external Na+ and H+ concentrations and on internal pH. These results provide evidence for the existence of a Na+/H+ antiport in pancreatic acinar cells. Caerulein, a cholecystokinin analog, stimulates the activity of the Na+/H+ antiport.