Porcine ileitis model induced by TNBS-ethanol instillation

Nine young pigs were used to evaluate the ability of an trinitrobenzene sulfonic acid-ethanol (TNBS-EtOH) mixture, in varying combinations, to induce ileitis comparable to that caused by intraintestinal instillation in other species. The distal ileum was accessed via laparotomy in anesthetized animals and the TNBS-EtOH was instilled via hypodermic needle. In three pigs in which the instillate was not held within an ileal segment, there were no ileal lesions noted upon necropsy at two weeks after instillation. In all six pigs in which the instillate was confined to a 10-cm length of distal ileum for 10-15 min, there was definite gross and histologic evidence of severe ileitis upon necropsy at one week after instillation. The histopathology was more consistent with Th-1- than Th-2-mediated inflammation.