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Biomedical subjects

A Bennett

Publications and source records attributed to A Bennett.

At least 307 records · Page 17Linked to original sources

Effects of prostaglandins E1 and E2 on human, guinea-pig and rat isolated small intestine.

1. Prostaglandins E(1) and E(2) contracted the longitudinal muscle of human, guinea-pig and rat isolated ileum.2. The site of action varied with the species. In the rat and in some strips of human tissue prostaglandin appeared to have only a direct action on or in the muscle cells. In the other strips of human tissue and in guinea-pig ileum the prostaglandins seemed to stimulate both the intrinsic cholinergic nerves and the muscle cells.3. In contrast to the longitudinal muscle, the circular muscle of human, guinea-pig and rat isolated ileum was usually inhibited by prostaglandin, apparently by an action directly on the muscle cells.4. Prostaglandins may play a part in the control of intestinal motility.

Acetylcholine↗

Effect of prostaglandins E1 and E2 on intestinal motility in the guinea-pig and rat.

1. Prostaglandins E(1) and E(2) affected intestinal activity both in vitro and in vivo.2. Serosal application of prostaglandin to guinea-pig isolated ileum stimulated the longitudinal muscle but reduced peristaltic contractions of the circular muscle and the propulsion of fluid through the gut. Intraluminal application had little effect.3. Injection of prostaglandin into the bloodstream of anaesthetized rats stimulated the longitudinal muscle of the ileum and increased the intraluminal pressure. A similar response sometimes occurred in the guinea-pig, but in general the effect was variable.4. Release of prostaglandin in the gut wall, but probably not into the blood or into the lumen of the gut, may play a part in controlling intestinal motility.

Animals↗

The release of 5-hydroxytryptamine from the rat stomach in vitro.

1. 5-HT was released into the lumen of the intact isolated rat stomach and into the bath fluid surrounding a preparation of the body and antrum stretched mechanically.2. Release of 5-HT increased when the pressure inside the intact stomach was raised or when the body/antrum preparation was stretched.3. This increased release was not prevented by hexamethonium, atropine, hyoscine or procaine, and was probably due to distortion of cells containing 5-HT.4. During periods of peristalsis induced by transmural stimulation the pharmacological activity of the fluid in the stomach was usually increased owing to a greater release of 5-HT and also to the release of an unidentified substance.5. In reserpine-treated rats, 5-HT was released into the stomach but transmural stimulation did not produce true peristalsis and only rhythmic contractions occurred.6. Peristalsis was seldom reduced by methysergide, and it is concluded that 5-HT is not essential for gastric peristalsis in the rat.

Animals↗