Effects of prostaglandins E2 and F2 alpha on motility of small intestine in man.

Interdigestive motility of the small intestine was examined in 23 fasted healthy volunteers following luminal administration of the prostaglandins E2 and F2 alpha. Motility was monitored by means of water-perfused catheters measuring intraluminal pressure changes. The registration points were located 25 cm apart, in the proximal duodenum, at the angle of Treitz, and in the jejunum. Prostaglandin E2 administered intraduodenally delayed the initiation of the subsequent activity front. The interval to the next activity front was prolonged by a dose of 1.0 mg prostaglandin E2 from 79.5 +/- 9.5 min to 137.1 +/- 5.0 min (P less than 0.01) and to 158.0 +/- 14.0 min by 2.0 mg prostaglandin E2 (P less than 0.05). Also, in four of seven experiments, a progressing activity front was arrested by 2.0 mg prostaglandin E2. Prostaglandin F2 alpha at 2.5 or 5.0 mg given intraduodenally induced bursts of contractions with a frequency of 17.7 +/- 0.8 contractions per minute and an amplitude of 10 to 110 mm Hg (P less than 0.01). In comparison, food intake produced irregular contractions at a frequency of 5.3 +/- 1.8 contractions per minute and an amplitude of 10 to 50 mm Hg (P less than 0.05). It is concluded that prostaglandin E2 delays the initiation of activity fronts in the duodenum. In contrast, prostaglandin F2 alpha changes the interdigestive motility pattern to one of intense contractile activity, which is different from the postprandial motility pattern.