Altered myoelectrical activity in noninflamed ileum of rats with colitis induced by trinitrobenzene sulphonic acid

Changes in gastric emptying and orocaecal transit time in patients with ulc erative colitis suggest that disturbances in gut motility may not be restri cted to inflamed sites. This study sought to characterize changes in the mo tility of noninflamed ileum in a rat colitis model and to explore the mecha nism(s) potentially involved. The myoelectrical activity of the ileum was r ecorded in rats with trinitrobenzene sulphonic acid (TNBS)-induced colitis. The degree of ileal and colonic inflammation was assessed by quantificatio n of macroscopic damage and myeloperoxidase activity (MPO). The effect on i leal motility of pretreatment with atropine, indomethacin and N-G-nitro-L-a rginine-methyl eater (L-NAME) was investigated TNBS-induced inflammation wa s restricted to the distal colon, as evidenced by morphological scores and MPO. Colitis was associated with increased frequency of ileal migrating mot or complexes, characterized mainly by a decrease in the duration of phases I and III. The occurrence of ileal giant migrating complexes remained uncha nged. The myoelectrical changes observed in the ileum persisted after treat ment with atropine, indomethacin and L-NAME. Distal colitis is associated w ith abnormal myoelectrical activity in the noninflamed ileum of rats. Neith er acetylcholine nor prostaglandins and nitric oxide seem to be involved.