PROTECTIVE ROLE OF VAGAL AFFERENTS IN EXPERIMENTALLY-INDUCED COLITIS IN RATS

The aim of this study was to evaluate the regulatory role of vagal aff erents in the development of colonic inflammation induced by trinitrob enzenesulfonic acid (TNBS) in rats. Groups of Wistar rats were treated with capsaicin or its vehicle applied perivagally (sham treatment). C olonic transit time was evaluated, and, two days later, one half of th e animals received an intracolonic instillation of TNBS/ethanol (40 mg /kg), and the other received saline. Inflammation was evaluated functi onally (gut permeability), biochemically (myeloperoxydase activity) an d histologically. Vagal capsaicin deafferentation did not modify colon ic transit time. In TNBS treated groups, inflammation was enhanced by capsaicin pretreatment, as determined by an increased gut permeability , MPO activity, and histological damage score. These results suggest t hat vagal afferents have a protective role in TNBS-induced colitis in rats, unrelated to changes in colonic transit time. (C) 1998 Elsevier Science B.V. All rights reserved.