The effect of SK-896 on post-operative ileus in dogs: gastrointestinal motility pattern and transit

Motilin: from gastric motility stimulation to hunger signalling

After the discovery of motilin in 1972, motilin and the motilin receptor were studied intensely for their role in the control of gastrointestinal motility and as targets for treating hypomotility disorders. The genetic revolution - with the use of knockout models - sparked novel insights into the role of multiple peptides but contributed to a decline in interest in motilin, as this peptide and its receptor exist only as pseudogenes in rodents. The past 5 years have seen a major surge in interest in motilin, as a series of studies have shown its relevance in the control of hunger and regulation of food intake in humans in both health and disease. Luminal stimuli, such as bitter tastants, have been identified as modulators of motilin release, with effects on hunger and food intake. The current state of knowledge and potential implications for therapy are summarized in this Review.

Interstitial cells of Cajal could regenerate and restore their normal distribution after disrupted by intestinal transection and anastomosis in the adult guinea pigs

Surgical manipulations of the gastrointestinal (GI) tract usually lead to loss of interstitial cells of Cajal (ICCs). The present study prepared to investigate whether ICCs can regenerate and restore their normal distribution up to 5 months after semitransection and end-to-end anastomosis of small intestines of adult guinea pigs. The segments of anastomosis were studied by immunohistochemistry with anti-KIT, 5-bromo-2'-deoxyuridine (BrdU), stem cell factor (SCF), and neurofilament 200 antibodies and also by transmission electron microscopy (TEM). At early stage, intestinal surgery led to intestinal wall impairment and ICCs loss, and ICCs near the site of anastomosis gradually increased in numbers. About 150 days postoperation, the distribution of ICCs and the microstructure of intestinal wall appeared to be similar with those of the control. By double immunostaining with BrdU and KIT antibodies, a number of proliferated ICCs were seen near the site of transection/anastomosis. Furthermore, KIT ligand, SCF, was mainly observed in the smooth muscle cells (SMCs), which are located close to ICCs. TEM observation revealed a number of immature and mature ICCs in this region. Our results indicated that ICCs could regenerate and restore their normal distribution after intestinal surgery and SMCs might be involved in the regenerated events of ICCs in the adult guinea pig GI tract.

Effects of SK-896, a new human motilin analogue ([Leu13]motilin-Hse), on postoperative ileus in dogs after laparotomy

The effects of SK-896, a new human motilin analogue ([Leu13]motilin-Hse), on digestive tract motility in postoperative ileus were evaluated in a dog model of ileus after laparotomy. SK-896 was intravenously administered at 0.17, 0.33 and 0.67 microg/kg starting soon after operation and then at 6-h intervals, for a total of 9 times. SK-896 progressively, dose-dependently and significantly increased the duodenal motility from 1 h after operation. The recovery time of the gastrointestinal-interdigestive migrating complex (GI-IMC) activity, which is an indicator of normal gastrointestinal tract activity after laparotomy, was 56.5 +/- 5.0 h in the control group. SK-896 significantly shortened this recovery time. On the other hand, the plasma SK-896 concentrations declined diexponentially after administration, and can be described by a linear pharmacokinetic model within the dose range used. In addition, the pharmacokinetics of SK-896 did not change significantly at any postoperative time. There was no correlation between the plasma SK-896 concentrations and the intensity of duodenal motility, because the activity in the duodenum decreased transiently 13 h after laparotomy and increased with time thereafter. The changes in the activity are considered to reflect the progressive changes in the state of ileus. In conclusion, SK-896 increased the duodenal motility significantly, shortening the recovery time of GI-IMC-like activity in dogs with post-laparotomy ileus. Therefore, it is expected from these results that SK-896 would be useful and effective for the treatment of gastroparalysis after abdominal surgery.