Inhibition of sympathetic pathways restores postoperative ileus in the upper and lower gastrointestinal tract

Background and Aim: Postoperative ileus (POI) is a transient bowel dysmotility following abdominal surgery. The effects of adrenergic blocking agents and celiac ganglionectomy were studied in rats to investigate the possible involvement of the adrenergic pathway in whole gastrointestinal (GI) transit in the early and late phases of POL. Methods: After laparotomy, the terminal ileum was manipulated for 10 min. Cr-51 was administered into the stomach or colon immediately after surgery. In another group, Cr-51 was administered 24 h after surgery. Three hours after Cr-51 was administered, the rats were killed, and GI and colonic transit was calculated as a geometric center (GC). Results: Gastrointestinal transit was significantly delayed 3 h after intestinal manipulation, compared with GI transit in rats that had anesthesia only. Three hours after intestinal manipulation, guanethidine (5 mg/kg) and yohimbine (3 mg/kg) significantly improved delayed GI transit. Celiac ganglionectomy also significantly improved delayed GI transit. Twenty-seven hours after intestinal manipulation, guanethidine, yohimbine and celiac ganglionectomy improved delayed GI transit induced by intestinal manipulation. Colonic transit was delayed 3 h after intestinal manipulation, and delayed colonic transit was partially restored within 27 h of intestinal manipulation. Guanethidine, yohimbine and celiac ganglionectomy improved delayed colonic transit 3 h and 27 h after intestinal manipulation. Conclusions: Adrenoceptors activated by intestinal manipulation impair the motility of the entire GI tract in both the early and the late phase of POI.