Prostaglandin stimulation of gastrointestinal transit in post-operative ileus rats.

The prostaglandins PGF2 alpha, PGE2 and 16,16-dimethyl PGE2, when administered intravenously, orally, subcutaneously or intraduodenally to laparotomized rats, decreased gastric emptying, small intestinal transit and colonic transit as compared to unoperated controls. All three prostaglandins increased colonic transit above that found with unoperated controls. This activity was independent of small intestinal fluid accumulation (i.e., enteropooling) since ligating the ileal-cecal junction had no effect on colonic transit. Small intestinal transit was increased, but not normalized, by PGE2 and 16,16-dimethyl PGE2. 16,16-Dimethyl PGE2 completely restored gastric emptying when given intravenously to laparotomized rats of doses greater than 5.0 microgram/kg. This effect on gastric emptying lasted approximately 4 hrs. Thus, 16,16-dimethyl PGE2, when given intravenously, normalized gastric emptying, significantly increased small intestinal transit, and made the colon hypermotile. Prostaglandins may be beneficial in the treatment of postoperative ileus and other conditions of sluggish gastrointestinal propulsion.