1. Dopamine D1 (central)/DA1 (peripheral) receptors are believed to influence gastrointestinal function and pathology. 2. When given i.c.v. or i.p., an agonist (SKF38393) and an antagonist (SCH23390) of this DA receptor subtype inhibit and enhance, respectively, gastric secretion and gastric mucosal injury. 3. When given both i.c.v. and i.p., their respective effects in the gut were amplified. 4. Antagonist or agonist given i.p., blocked the corresponding protective and worsening effect of the agonist or antagonist given i.c.v. 5. Both central and peripheral D1/DA1 receptors modulate gastric function and response to injury.