Original Article Elmer ress J Clin Med Res • 2011;3(2):78-84 Protective Effects of L-Carnitine on Intestinal Ischemia/Reperfusion Injury in a Rat Model Yong Yuana, Hao Guob, Yi Zhanga, Dong Zhoua, Ping Gana, Dao Ming Lianga, Jia Yong Chena, c Abstract Background: Ischemia/reperfusion (IR) injury of the intestine is a major problem in abdominal pathological condition and is associ- ated with a high morbidity and mortality. The purpose of the study is to determine whether the L-carnitine can prevent the harmful ef- fects of small intestinal IR injury in rats. Methods: Thirty Sprague-Dawley rats were randomly divided into three groups. Sham operated group (S), for sham–operated, the IR group for rats submitted to 45-minute of intestinal ischemia and 2-hour reperfusion, and IR+L group for those IR group treated with L-carnitine before reperfusion. All the rats were given EmGFP la- belled E. coli DH5α through gavage 2-hour before the operative procedure. Afterwards the bacterial translocation (BT) from mes- enteric lymph nodes (MLN), liver, spleen, lung and portal vein blood were detected. And the colony forming units/g (CFU/g) were counted. The TNF-α, IL-1β, IL-6, and IL-10 in serum were mea- sured by ELISA. The morphometric study was measured by Chiu’s classiﬁcation. Results: The levels of BT were higher in the IR group than IR+L group (P < 0.05). The E. coli DH5α was hardly detected in the S group. The IR+L rats had enhancement of IL-10 and suppressed production of serum TNF-α, IL-1β and IL-6, compared to IR group rats (P < 0.05). The degree of pathological impairment in small in- testine was lighter in IR+L than IR group (P < 0.05). Conclusions: The L-carnitine pretreatment has a positive effect on reducing levels of BT, on inhibiting secretion of proinﬂammatory cytokines, and on lessening intestinal mucosa injury during small intestinal IR injury. Manuscript accepted for publication March 21, 2011 aDepartment of Emergency, The Second Afﬁliated Hospital of Kunming Medical College, Kunming, Yunnan 650101, China bDepartment of Cardiology, Calmette Hospital, Kunming Medical College, Kunming, Yunnan 650011, China cCorresponding author: Jia Yong Chen, Email: CJY125@163.com doi:10.4021/jocmr540w Keywords: L-carnitine; Ischemia/reperfusion injury; Intestine Introduction The gastrointestinal tract is a tissue which is highly sensi- tive to ischemia-reperfusion (IR) injury in the body [1]. The intestinal IR injury is caused by many clinical conditions, including acute mesenteric ischemia, intestinal obstruction, incarcerated hernia, small intestine transplantation, neona- tal necrotizing enterocolitis, trauma, and shock [2-4]. It is extremely dangerous and emergent for patients to have in- testinal IR injury because it may result in an array of severe clinical syndromes, and even death [5]. Under the normal physiological situation, the maintenance of bacteria and their products in the intestine depends on mucosal mucin and a layer of epithelial cells, and the unbroken intestinal barrier is essential for health and survival. In addition, the epithelial cells have high metabolism activity, and it is also susceptible to oxygen deprivation with subsequent ischemia damage to enterocytes and their supporting structures [6]. The impair- ment of the intestinal barrier may lead to decrease in absorp- tion of nutrition, and the bacteria in the intestine may trans- locate to blood and other organs due to the damage of the intestinal barrier. The consequences of the bacterial translo- cation (BT) and release of harmful substances produced by the bacteria into blood circulation are to activate inﬂamma- tory mediators and initiate Systemic Inﬂammatory Response (SIRS) or Multiorgan Dysfunction Syndrome (MODS) [7, 8]. Thus, there is a great interest in exploring methods to protect the small intestine from lesions. L-carnitine is an im- portant active material, which plays a crucial role in energy metabolism. The shortage of L-carnitine includes metabo- lism disruption and induction of a series of disorders. Xie et al’s study has demonstrated that L-carnitine has a protective effect on IR injury, which is partly due to its prevention of energy loss and its antioxidant activity [9]. Moreover, it has a protective effect on oxidative stress-induced DNA dam- age [10]. Oyanagi et al’s study [11] has demonstrated that L-carnitine can maintain mitochondrial function and sup- 78 Articles © The authors | Journal compilation © J Clin Med Res and Elmer Press™ | www.jocmr.org