Aim: To demonstrate the change and effect of nociceptin/orphanin FQ in the colon of rats with cathartic colon.
Methods: The cathartic colon model was established by feeding rats rhubarb for 3 mo, the changes of colonic electromyography were investigated by both suspension muscle strips test and serosal recordings of colonic myoelectrical activity. Immunohistochemical staining (S-P methods) and image analysis were used to determine the changes of nociceptin/orphanin FQ in the proximal colon and distal colon of rats with cathartic colon.