Efficacy of Hyperbaric Oxygen Therapy and Medical Ozone Therapy in Experimental Acute Necrotizing Pancreatitis Bulent Uysal, MD,* Mehmet Yasar, MD,Þ Nail Ersoz, MD,Þ Omer Coskun, MD,þ Abdullah Kilic, MD,§ Tuncer CaycN, MD,|| Bulent Kurt, MD,¶ Sukru Oter, MD,* Ahmet Korkmaz, MD,* and Ahmet Guven, MDL Objectives: Our aims were to evaluate the efficacy of ozone therapy (OT) in an experimental rat model of acute necrotizing pancreatitis (ANP) and to compare its effects with hyperbaric oxygen (HBO) therapy in this entity. Methods: Forty Sprague-Dawley rats were divided into sham-operated, ANP, ANP + HBO, and ANP + OT groups. Acute necrotizing pan- creatitis was induced by infusing 1-mL/kg 3% sodium taurocholate into the common biliopancreatic duct. Hyperbaric oxygen was adminis- tered twice daily at a 2.8-atm pressure for 90 minutes. Ozone therapy was set as daily intraperitoneal injections of 0.7-mg/kg ozone/oxygen gas mixture. Hyperbaric oxygen and OTwere continued for 3 days after the induction of ANP. The surviving animals were killed at the fourth day, and their pancreases were harvested for biochemical, microbiolog- ical, and histopathologic analyses. Results: Serum amylase/lipase and neopterin levels and tissue oxida- tive stress parameters were similar to sham’s values in both the ANP + HBO and the ANP + OT groups. Histopathologic injury scores were significantly lower in the treatments groups than in the ANP group. When compared with the ANP group, the number of infected rats was significantly lesser in the ANP + HBO and the ANP + OT groups. Conclusions: Hyperbaric oxygen and OT reduce the severity and the mortality in the experimental rat model of ANP, and a greater benefit was received for OT comparing with HBO. Key Words: acute necrotizing pancreatitis, ozone therapy, hyperbaric oxygen therapy, bacterial translocation, oxidative stress (Pancreas 2010;39: 9Y15) A cute necrotizing pancreatitis (ANP) remains a major challenge to gastroenterologists, surgeons, and intensivist. Acute necrotizing pancreatitis induces a massive inflammatory reaction resulting from an imbalance between the systemic release of proinflammatory and anti-inflammatory mediators that results in multiple organ failure sepsis. 1 In addition, reactive oxygen species (ROS), such as superoxide (O 2 j ), hydrogen peroxide (H 2 O 2 ), and hydroxyl radicals (OH j ), and reactive nitrogen species (RNS), such as peroxynitrite (ONOO j ), have been accused as an important factor in the pathogenesis and progress of the pancreatitis. 2,3 It is well known that recruitment of activated neutrophils and monocytes into the pancreatic interstitium also cause further exacerbated pancreatic damage via the generation of ROS/RNS. 4 Although some of the mechanisms of action of hyperbaric oxygen (HBO) therapy are yet to be discovered, it is known that HBO increases oxygen concentration in all body tissues, even with reduced or blocked blood flow; stimulates the growth of new blood vessels, improving blood flow to compromised or- gans; stimulates an adaptive increase in superoxide dismutase (SOD); and aids the treatment of infection by enhancing white blood cell action. 5,6 The reports from our institute have displayed that HBO reduces oxidative stress in pancreatic tissue with pancreatitis. 7,8 Nikfarjam et al 9 have found that HBO therapy reduced the severity of the disease and improved the survival rates in rats with severe acute pancreatitis. Moreover, Festugato et al 10 have investigated the effects of HBO therapy on tissue lesions in an experimental model of acute pancreatitis, and they have shown that HBO therapy is efficient in reducing hemorrhage and acinar necrosis but is not sufficient to reduce edema and leukocyte infiltration. However, its probable role in extenuating the pathophysiological effects of acute pancreatitis has not been fully clarified. A gas mixture comprising ozone/oxygen used in medicine is known as medical ozone therapy (OT). Ozone/oxygen mixture exhibits various effects on the immune system, such as the modulation of phagocytic activity of peritoneal and alveolar macrophages. 11Y13 Clinical studies have so far shown that OT seems useful in diseases including peritonitis, infected wounds, chronic skin ulcers, initial gangrene, burns, and advanced ischemic diseases. 13,14 In addition, administration of ozone induced a sort of cross-tolerance to free radicals released af- ter hepatic and renal ischemia-reperfusion in experimental studies. 15,16 It was also demonstrated that ozone increases antioxidant enzyme activities such as glutathione peroxidase (GSH-Px), SOD, and catalase, preparing the host to face physio- pathologic conditions mediated by ROS. 12,17 We recently re- ported that OT has an ameliorative effect in reducing oxidative stress in caustic esophageal burn and necrotizing enterocolitis in an experimental rat model. 18,19 The introduction of new strategies for treatment of AP is important to decrease morbidity and mortality. Therefore, we designed an experimental study to evaluate and to compare the efficacy of HBO and OT in an experimental model of AP in rats. MATERIALS AND METHODS Animals and Study Groups All animal procedures were approved by the institutional committee on the care and use of animals of our institution (issue; 08/31). Forty male Sprague-Dawley rats (200Y250 g) provided by the animal laboratory of our institute were randomly assigned into 4 groups containing 10 rats each: sham-operated, ORIGINAL ARTICLE Pancreas & Volume 39, Number 1, January 2010 www.pancreasjournal.com 9 From the Departments of *Physiology, †General Surgery, ‡Infectious Diseases, §Clinical Microbiology, ||Clinical Biochemistry, ¶Pathology, and LPediatric Surgery, Gulhane Military Medical Academy, Ankara, Turkey. Received for publication February 28, 2009; accepted July 16, 2009. Reprints: Ahmet Guven, MD, Department of Pediatric Surgery, Gulhane Military Medical Faculty, Etlik, Ankara, Turkey 06018 (e-mail: drahmetguven@yahoo.com). Copyright * 2009 by Lippincott Williams & Wilkins 9 Copyright @ 200 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.