Improvement of intestinal motility using S-methylisothiourea in postoperative ileus

Background The inflammatory mediator nitric oxide (NO) plays an important role in postoperative gastrointestinal motility. Methods Using S-methylisothiourea sulfate (SMT), a selective inducible nitric oxide synthase inhibitor, we studied the physiological role of the endogenous NO in the modulation of intestinal motility. The study was performed in vivo in a canine postoperative model. Ten mongrel dogs were treated with a continuous intravenous infusion of SMT after a surgical intestinal manipulation. Small intestine transit time was fluoroscopically measured using barium sulfate as it passed through a gastrostomy tube on postoperative days (POD) 1, 2, and 3. Results Average transit times on POD 1 in the 4 mg/kg/h and 2 mg/kg/h SMT groups significantly decreased compared with that of the saline group. However, the transit times on POD 2 and 3 were not significantly different among the three groups. Conclusions S-methylisothiourea sulfate improves small intestine motility at an early postoperative stage.