Effect of ischemic postconditioning and atorvastatin in the prevention of remote lung reperfusion injury

Abstract Objective: The aim of the present study was to evaluate the ability of ischemic postconditioning, atorvastatin and both associated to prevent or minimize reperfusion injury in the lung of rats subjected to ischemia and reperfusion by abdominal aortic clamping. Methods: We used 41 Wistar norvegic rats, which were distributed into 5 groups: ischemia and reperfusion (I/R), ischemic postcondictioning (IPC), postconditioning + atorvastatin (IPC+A), atorvastatin (A) and SHAM. It was performed a medium laparotomy, dissection and isolation of the infra-renal abdominal aorta; except for the SHAM group, all the others were submitted to the aortic clamping for 70 minutes (ischemia) and posterior clamp removal (reperfusion, 70 minutes). In the IPC and IPC+A groups, postconditioning was performed between the ischemia and reperfusion phases by four cycles of reperfusion and ischemia lasting 30 seconds each. In the IPC+A and A groups, preceding the surgical procedure, administration of 3.4 mg/day of atorvastatin was performed for seven days by gavage. After the surgical procedure, the right caudal lobe was removed from the lung for histological study, using tissue injury score ranging from grade 1 (normal tissue) to grade 4 (intense lesion). Results: The mean lung injury was 3.6 in the I/R group, 1.6 in the IPC group, 1.2 in the IPC+A group, 1.2 in the A group, and 1 in the SHAM group (P<0.01). Conclusion: Ischemic postconditioning and atorvastatin were able to minimize lung reperfusion injury, alone or in combination.

Effect of postconditioning and atorvastatin in preventing remote intestinal reperfusion injury / Efeito do pós-condicionamento e da atorvastatina na prevenção de lesão de reperfusão intestinal remota

ABSTRACT Objective: To evaluate the capacity of ischemic postconditioning and atorvastatin in prevent or minimize reperfusion injury in small bowel of rats subjected to ischemia and reperfusion by abdominal aorta clamping. Methods: 41 Wistar norvegic rats were distributed into 5 groups: ischemia and reperfusion, ischemic postconditioning, postconditioning + statin, statin and Sham. After anesthesia, laparotomy and dissection of the infra-renal abdominal aorta were performed; except the Sham group, all others were subjected to aorta clamping for 70 min (ischemia) and withdrawal of clamp for 70 min (reperfusion). In the IPC and IPC + S groups, four cycles of postconditioning were performed between the phases of ischemia and reperfusion lasting 30 s each. In IPC + S and S groups, 3.4 mg/day of atorvastatin was given for seven days per gavage; 1 cm of the ileum were removed for histological study and the results were subjected to statistical treatment considering significant p < 0.05. Results: The average of intestinal lesion was 2 in the I/R group, 0.66 in the IPC group, 0 in the IPC + S group, 0 in the S group, and 0 in the SHAM group. Conclusion: The ischemic postconditioning and atorvastatin were capable of minimizing intestinal reperfusion injury, either alone or in combination.

RESUMO Objetivo: Avaliar a capacidade do pós-condicionamento isquêmico e da atorvastatina para prevenir ou minimizar a lesão de reperfusão no intestino Delgado de ratos submetidos à isquemia e reperfusão por pinçamento de aorta abdominal. Métodos: 41 ratos noruegueses Wistar foram distribuídos em 5 grupos: isquemia e reperfusão, pós-condicionamento isquêmico, pós-condicionamento + estatina, estatina e simulacro. Depois da anestesia, procedeu-se à laparotomia e dissecação da aorta abdominal infrarrenal; exceto no grupo de simulacro, todos os demais grupos foram submetidos ao pinçamento da aorta durante 70 minutos (isquemia) e à retirada do pinçamento também durante 70 minutos (reperfusão). Nos grupos PCI e PCI + E, foram efetuados quatro ciclos de pós-condicionamento entre as fases de isquemia e de reperfusão, com duração de 30 segundos cada. Nos grupos PCI + E e E, foram administrados 3,4 mg/dia de atorvastatina durante 7 dias por gavagem; procedemos à remoção de 1 cm do íleo para o estudo histológico, e os resultados foram estatisticamente tratados. Consideramos p < 0,05 como estatisticamente significativo. Resultados: As médias para as lesões intestinais foram 2 no grupo I/R, 0,66 no grupo PCI, 0 no grupo PCI + E, 0 no grupo E, e 0 no grupo S. Conclusão: O procedimento de pós-condicionamento e atorvastatina demonstraram capacidade de minimizar a lesão de reperfusão intestinal, tanto isoladamente como em conjunto.