Mode of Action of Acetazolamide on Pancreatic Exocrine Secretion

In unanesthetized dogs with chronic gastric and pancreatic fistulas, an intravenous infusion of acetazolamide (Diamox), superimposed on a steady-state infusion of secretin, caused a prompt reduction in the volume and bicarbonate concentration of pancreatic secretion and a delayed reduction in potassium concentration. These changes were not caused by alterations in serum electrolytes or by the development of a metabolic acidosis. The reductions in volume and bicarbonate concentration were too rapid and extensive to be accounted for by compensatory respiratory mechanisms, and hence reflect a direct effect of acetazolamide on pancreatic secretion. Reductions in bicarbonate concentration during the infusion of acetazolamide appeared to bear a physiologic relationship to the induced slower flow rates.