Dose response inhibition in man of meal-stimulated gastric acid secretion by 15(R)-15-methyl prostaglandin E2, given orally.

15(R)-15-methyl prostaglandin E2 was given orally to healthy male volunteers. Thirty minutes later a 10% peptone meal was introduced into the stomach, and the acid response was measured by continuous intragastric titration with 0.5 N NaOH for the next two hours. The prostaglandin inhibited acid output in a dose dependent manner; the ED50 (dose inhibiting acid output by 50%) was as little as 10 micrograms per subject (or approximately 140 ng/kg). This compound is the most potent orally active inhibitor of gastric acid secretion in man that is known. It is likely that the antisecretory and cytoprotective properties shared by 15(R)-15-methyl prostaglandin E2 would be beneficial in the treatment of peptic ulcer and in preventing recurrences.