Effect of TKS159, a novel 5-hydroxytryptamine4 agonist, on gastric contractile activity in conscious dogs

Mosapride citrate improves postoperative ileus of patients with colectomy

BACKGROUND AND AIMS

Postoperative ileus is a transient bowel dysmotility that occurs following many types of operations and is a common complication of gastrointestinal surgery. Mosapride citrate is an agonist of the 5-hydroxytryptamine 4 receptor and accelerates upper gut motility. No study has evaluated its effect on gastrointestinal motility after surgery. The aim of this study was to investigate whether mosapride citrate reduces the duration of postoperative ileus.

METHODS

Thirty patients with colon cancer who underwent colectomy were divided into two groups: the mosapride group and the control group. The mosapride group received mosapride 15 mg by mouth with a minimal amount of water three times a day, starting on postoperative day 1. The control group received only a minimal amount of water on the same schedule. Patients were allowed to resume oral feeding on postoperative day 4. Postoperative time to first flatus and defecation were evaluated, and the amount of food intake was observed. Gastrointestinal motility was recorded on postoperative day 8.

RESULTS

The appearance ratio of interdigestive migrating contractions and the motility index at the antrum and duodenum were significantly higher in the mosapride group than in the control group. The time to first flatus and defecation were significantly shorter in the mosapride group than in the control group. The amount of food intake on postoperative days 6 and 7 was significantly larger in the mosapride group than in the control group.

CONCLUSION

Mosapride citrate reduces the duration of postoperative ileus and may improve outcomes after gastrointestinal surgery.

In vitro effects of 5-hydroxytryptamine and cisapride on the circular smooth muscle of the jejunum of horses

OBJECTIVE

To determine effects of cisapride and 5-hydroxytryptamine (5-HT) on the jejunum of horses.

SAMPLE POPULATION

Jejunal muscle strips from 8 horses.

PROCEDURE

Muscle strips were suspended in isolated muscle baths. Isometric stress responses to 5-HT and cisapride, with and without specific antagonists, were determined.

RESULTS

Muscle strips incubated with atropine and tetrodotoxin responded to 5-HT and cisapride with an increase in contractile force. The 5-HT caused a concentration-dependent increase in contractile amplitude, with a maximum response (Emax) of 1,151+/-214 g/cm2 and a molar concentration that induces contractile force equal to 50% of maximum response (EC50) of 0.028+/-0.002 microM. Prior incubation with the 5-HT2 antagonist ketanserin decreased the Emax (626 +/-147 g/cm2) and potency (EC50, 0.307+/-0.105 microM) of 5-HT Prior incubation with the 5-HT3 antagonist tropisetron decreased the efficacy (Emax, 894+/-184 g/cm2) to 5-HT Cisapride also caused a concentration-dependent increase in contractile amplitude, with an Emax of 331+/-82 g/cm2 and an EC50 of 0.302+/-0.122 microM. Prior incubation with ketanserin decreased the Emax (55+/-17 g/cm2) and potency (EC50, 0.520+/-0.274 microM) of cisapride.

CONCLUSION AND CLINICAL RELEVANCE

Stimulatory effects of 5-HT and cisapride on circular smooth muscle of equine jejunum are mediated primarily through a noncholinergic effect. The effects of 5-HT are mediated, at least partially, by 5-HT2 and 5-HT3 receptors, whereas the effects of cisapride are mediated primarily by 5-HT2 receptors. This may impact treatment of horses with postoperative ileus.

Gastroduodenal motility

Several major themes emerged over the past year in the area of gastroduodenal motility. Mostly, these themes represented extensions of research areas discussed in prior reviews in this series rather than the emergence of completely new concepts. Thus, for example, considerable emphasis has again been placed on regional gastric motor function in dyspepsia and on the role of fundic relaxation and accommodation, in particular. Not surprisingly, basic physiologic research has also shown a keen interest in the regulation of fundic relaxation. One new and exciting development is the recognition of the stomach's role in satiety. The spectrum of gastric motor dysfunction in diabetes mellitus continues to be explored, and the important role of hyperglycemia in regulating gastric function has been further emphasized. More data have been provided on noninvasive alternatives to gastric motor function testing, and several studies have looked at factors that may influence variability in these various tests. There have been few innovations over the past year in the therapeutic arena; rather, the indications and limitations of current therapies have been further developed.