[An experimental study of the action of dopamine in suppressing pentagastrin stimulated gastric acid secretion and its mechanism in rats].

The action of dopamine (DA, 10 micrograms/kg/min) on pentagastrin (16 micrograms/kg/hr) stimulated gastric acid secretion was studied by use of Ghosh-Schild's rats. DA suppressed pentagastrin-stimulated gastric acid secretion 44.6 percent compared with the level before administration. This decrease in acid was inhibited by pretreatment with beta 1 and beta 1 + beta 2 blockers and pretreatment with DA1 + DA2 and DA1 antagonists. The gastric acid secretion with DA1 agonist decreased 36.4 percent from the level at the time of pentagastrin administration. This decrease was inhibited by pretreatment with beta 1 blocker, but suppression of gastric acid secretion by beta 1 + beta 2 stimulator was not inhibited by pretreatment with DA1 antagonist. These results suggest that DA stimulated beta 1 adrenalin receptor via DA1 receptor and thereby suppresses pentagastrin-stimulated gastric acid secretion.