Morphine Decreased Peritoneal Adhesion in Addicted Male Rats after Abdominal Surgery

Introduction Peritoneal adhesions have been reported as an adverse side effect of surgery for more than a century and occur in 90-100% of cases. Postoperative adhesion formation results from a series of local events at the trauma site. Peritoneal injury by surgery, infection, or irritation initiates a local inflammatory reaction, exudation, and fibrin deposition into which white blood cells; macrophages, fibroblasts, and mesothelial cells can migrate, proliferate, and/or differentiate. Within a few hours the lesion is filled by macrophages and other tissue repair cells whose exact precursors are still unclear. Postoperative adhesion formation is an important clinical problem after abdominal surgery. Chronic abdominal pain, feeding intolerance, bowel obstruction, need for reoperative surgery, and female infertility are the most common problems related to postoperative intraabdominal adhesions that threat the patients health. Numerous agents such as phospholipase inhibitors, dextran, corticosteroids, phospholipids, methylene blue, antiinflammatory drugs, polysaccharides, bioresorbable membranes, tissue plasminogen activator, and Ankaferd blood stopper have been studied to prevent adhesion formation. The mechanisms related to peritoneal adhesion is not well studied but it is believed that inflammation has the major role. Inflammations caused by mechanical stimuli are the principal causes of intraperitoneal adhesions. During infection, in contrast, the opioid concentration increases in the peripheral blood and at the sites of inflammatory reaction. In addition, opioid receptor is expressed in macrophages, indicating that opioid peptides produced during inflammation can stimulate opioid receptor. Morphine is the main alkaloid of opium. Morphine has been shown to suppress several immune parameters, including lymphocyte proliferation and natural killer cell activity. The administration of morphine mediates a histamine release. In addition to morphine’s known effect on histamine release data suggest that it may also play a role in altering the immune response. The number of people who addicted to morphine is high in Iran and epidemiologic studies showed less peritoneal adhesion occurred in those patients. Therefore, our study designed to investigate effects of morphine on reduction of abdominal adhesion after surgery in normal or addicted animals.