Gastric juice electrolyte secretion in conscious dogs with gastric fistulae and its modification by FPL 52694, a mast cell stabilizing agent.

Studies have been made of the electrolyte output in the gastric juice of conscious dogs equipped with gastric fistulae during stimulation by intravenous infusion of either pentagastrin (2 micrograms kg-1 h-1), histamine (30 micrograms kg-1 h-1) or insulin (0.1 u kg-1 h-1). The mast cell stabilizing agent, FPL 52694 (4.35 mg ml-1) was instilled into the stomach for 30 min and caused a marked reduction of H+ output, H+ concentration and osmotic strength of the juice during stimulation with pentagastrin, histamine, or insulin. There was also a marked increase in the rate of Na+ output into the juice. When pentagastrin-stimulated acid secretion was inhibited by cimetidine (4 mumol kg-1 i.v.) acid output was reduced but there were no sustained changes in ion concentrations, osmolarity or Na+ output of the type seen following inhibition with FPL 52694. It is concluded that FPL 52694 may have a dual mode of action in this preparation; a direct reduction of the output of hydrochloric acid and a smaller effect to increase gastric NaHCO3 output leading to a post-secretory neutralization of the juice.