The Effect of Ethyl Pyruvate on Oxidative Stress in Intestine and Bacterial Translocation After Thermal Injury Melih Karabeyog ˘ lu, M.D.,* ,1 Bu ¨ lent U ¨ nal, M.D.,* Betu ¨ l Bozkurt, M.D.,* Is ¸tar Dolapçı, M.D.,† Ays ¸e Bilgihan,‡ Is ¸ıl Karabeyog ˘lu, M.D.,§ and O ¨ mer Cengiz, M.D.* *Department of 2nd General Surgery, Numune Education and Research Hospital, Ankara, Turkey; †Department of Microbiology, Faculty of Medicine, Ankara University, Ankara, Turkey; ‡Department of Biochemistry, Faculty of Medicine, Gazi University, Ankara, Turkey; and §Department of Anesthesiology and Reanimation, Numune Education and Research Hospital, Ankara, Turkey Submitted for publication November 2, 2006 Background. Thermal injury causes a breakdown in the intestinal mucosal barrier due to ischemia reperfusion injury, which can induce bacterial translocation (BT), sep- sis, and multiple organ failure in burn patients. The aim of this study was to investigate the effect of ethyl pyruvate (EP) on intestinal oxidant damage and BT in burn injury. Materials and methods. Thirty-two rats were ran- domly divided into four groups. The sham group was exposed to 21°C water and injected intraperitoneal with saline (1 mL/100 g). The sham  EP group received EP (40 mg/kg) intraperitoneally 6 h after the sham proce- dure. The burn group was exposed to thermal injury and given intraperitoneal saline injection (1 mL/100 g). The burn  EP group received EP (40 mg/kg) intraperitone- ally 6 h after thermal injury. Twenty-four hours later, tissue samples were obtained from mesenteric lymph nodes, spleen, and liver for microbiological analysis and ileum samples were harvested for biochemical analysis. Results. Thermal injury caused severe BT in burn group. EP supplementation decreased BT in mesenteric lymph nodes and spleen in the burn  EP group com- pared with the burn group (P < 0.05). Also, burn caused BT in liver, but this finding was not statistically signifi- cant among all groups. Thermal injury caused a statisti- cally significant increase in malondialdehyde and myelo- peroxidase levels, and EP prevented this effects in the burn  EP group compared with the burn group (P < 0.05). Conclusion. Our data suggested that EP can inhibit the BT and myeloperoxidase and malondialdehyde production in intestine following thermal injury, sug- gesting anti-inflammatory and anti-oxidant properties of EP. © 2008 Elsevier Inc. All rights reserved. Key Words: intestinal mucosal barrier; thermal in- jury; ethyl pyruvate; bacterial translocation. INTRODUCTION Although the management of thermal injury has progressed in recent years, its complications such as systemic inflammatory response syndrome, sepsis, and multiple organ failure still continue to be the principal causes of mortality and morbidity [1]. Normally in the gut, there is homeostasis between the intraluminal bacteria, their products, and intestinal mucosal barrier [2]. Thermal cutaneous injury causes a breakdown in the intestinal mucosal barrier, which can induce bac- terial translocation (BT), and thus septic complications and multiple organ failure in burn patients. After ther- mal injury, a transient and selective splanchnic vaso- constriction occurs which is related to decrease mesen- teric blood flow and damage of the mucosal barrier due to ischemia reperfusion (I/R) injury, which promotes BT from the gut [3]. Pathophysiological mechanisms that lead to the injury of the mucosal barrier include the adhesion and activation of polymorphonuclear neu- trophils, the release of pro-inflammatory cytokines, as well as the formation of reactive oxygen species (ROS), such as hydroxyl radical, superoxide anion, hydrogen peroxide, and reactive nitrogen species, such as nitric oxide and peroxynitrite [4]. ROS are thought to play a major role in the pathogenesis of structural and func- tional alterations in the tissues, which are related to a variety of pathologic processes, such as sepsis and sep- tic shock [5, 6], hemorrhagic shock [7], and thermal injury [8]. Pyruvate, a small molecule that normally is re- garded as a key intermediate in the oxidative or an- aerobic metabolism of glucose, is also a potent and effective ROS scavenger [9, 10]. Pyruvate’s antioxidant properties stem in part from its alpha-keto-carboxylate structure, which enables it to directly nonenzymati- cally neutralize peroxides and peroxynitrite [11]. It has 1 To whom correspondence and reprint requests should be ad- dressed at Bascavus Sok. Ugur Apt. 20/4, Kucukesat, Cankaya, 06660, Ankara, Turkey. E-mail: melihkrb@yahoo.com. Journal of Surgical Research 144, 59 – 63 (2008) doi:10.1016/j.jss.2007.02.050 59 0022-4804/08 $32.00 © 2008 Elsevier Inc. All rights reserved.