Acta Cirúrgica Brasileira - Vol. 29 (supl. 2) 2014 - 67 13 – ORIGINAL ARTICLE ISCHEMIA-REPERFUSION Heart injury following intestinal ischemia reperfusion in rats is attenuated by association of ischemic preconditioning and adenosine 1 Micaela Frasson Montero I , Rafael Saurim II , Wesley Guedes Sava Bonservizi II , Marcia Kiyomi Koike III , Murched Omar Taha IV DOI: http://dx.doi.org/10.1590/S0102-8650201400140013 I Medical student at ABC Medical School, Santo André, SP, Brazil. Scientifc Initiation Project. Data acquisition, analysis and interpretation of data, responsible for manuscript writing. II Medical student at Federal University of São Paulo – UNIFESP, São Paulo, SP, Brazil. Data acquisition, analysis and interpretation of data, responsible for manuscript preparation. III PhD, Laboratory of Emergency Medicine – LIM-51, Faculty of Medicine of São Paulo University, Sao Paulo, Brazil. Interpretation of data, histopathological, statistical analysis and critical revision. IV PhD, Associate Professor, Operative Technique and Experimental Surgery Division, Department of Surgery, UNIFESP, Sao Paulo, Brazil. Main author. Responsible for conception, design, intellectual and scientifc content of the study. Final approval of the version to be published. ABSTRACT PURPOSE: To investigate the effect of ischemic preconditioning (IPC) and adenosine as strategies to protect cardiac injury caused by intestinal IR in rats, based on increasing in adenosine bioavailability and improvement of cell energy state by IPC. METHODS: Male Wistar rats were submitted to 60 minutes of intestinal ischemia and 120 minutes of reperfusion. Intravenous injections of saline or Adenosine (AD) was administered fve minutes before ischemia, fve minutes before reperfusion and after 55 minutes reperfusion. Cardiac samples were obtained, fxed in formalin solution, embedded in paraffn, and sections of 5 μm were stained by hematoxylin-eosin. Histological analysis of myocardium was performed according occurrence of necrosis signs: piknosis, band contraction, eosinophilic cytoplasm, karyorrhexis and vacuolization (score - zero to 5). RESULTS: The groups submitted to ischemia alone (I=4.0), and reperfusion (IR=4.5) showed highest level of lesion compared to the others (I+IPC=3.3, IR+IPC=3.6, I+AD=3.0, IR+AD=3.8). The most interesting result was association of IPC and AD in IR model (IR+IPC+AD=1.2, p=0.002), showing preservation of the heart tissue, with fbers showing typical cross-striations and nuclei characteristics. Rare and small areas of tissue necrosis was observed and suggestion of capillaries congestion. CONCLUSION: Intestinal ischemia reperfusion promotes cardiac tissue injury. Ischemic preconditioning in association with adenosine is an effcient strategy to protect the heart against ischemia and reperfusion injury. Key words: Adenosine. Ischemic preconditioning. Intestinal ischemia/reperfusion. Heart. Rats.