Gastric effects of a prostaglandin E1-derivate (rioprostil) on acid, alkaline, and mucus secretion.

In a double-blind crossover study, the gastric effects of a single oral dose of rioprostil (150 and 300 micrograms) or placebo were compared in basal conditions and during a 120-minute pentagastrin infusion. A slight decrease in basal acid output and a nonsignificant rise in basal bicarbonate secretion were observed with the 300-micrograms dose. Pentagastrin-stimulated acid secretion was reduced by the prostaglandin derivate, especially with the 300-micrograms dose. Compared with placebo, 300 micrograms of rioprostil significantly stimulated basal mucoprotein secretion and bicarbonate and mucus output during pentagastrin infusion. The results suggest that 300 micrograms of rioprostil exerts both a moderate antisecretory activity and a strengthening effect on the gastric mucus-bicarbonate barrier.