Effect of two methylated prostaglandin E2 analogs on gastroduodenal pressure in man

The effect of two methylated analogs of prostaglandin E2 (PGE2), namely 16, 16-dimethyl PGE2 and 15 (S)-15-methyl PGE2 methyl ester, on gastroduodenal motility has been studied in healthy male volunteers. Oral administration of 140 mug of the 16-alkylated analog produced a significant decrease in motor activity in both the gastric antrum and the duodenum. 80 mug had no detectable effect on pressure. However, 80 mug of the 15-methylated analog administered directly into the duodenum caused an almost immidiated inhibition of the duodenal motor activity. In view of previous findings on the inhibitory action of these two analogs on gastric acid secretion, it seems as if the gastrointestinal smooth muscles are less sensitive to the action of the analogs than are the oxyntic glands.