Avaliação do pós-condicionamento isquêmico no tratamento da isquemia mesentérica: estudo experimental em ratos

Abstract

Avaliação do pós-condicionamento isquêmico no tratamento da isquemia mesentérica. Estudo experimental em ratosEvaluation of ischemic postconditioning effect on mesenteric ischemia treatment. Experimental study in rats Abstract Objective: To assess the preconditioning and postconditioning effect on intestinal mucosal lesions in rats undergone mesenteric ischemia and reperfusion procedure.Methods: Thirty Wistar rats were studied and divided into three groups: Group A, 10 rats undergone mesenteric ischemia (30 minutes) and reperfusion (60 minutes); Group B, 10 rats undergone mesenteric ischemia and reperfusion preceded by ischemic preconditioning for three cycles of ischemia and reperfusion for two minutes each; Group C, 10 rats undergone mesenteric ischemia and reperfusion and, preceding the beginning of reperfusion, ischemic postconditioning was performed for three cycles of reperfusion and ischemia for two minutes each. Then, a segment of small intestine was resected for histological analysis. We assessed the results by Chiu et al. score and the statistical analysis was performed.Results: According to Chiu et al. score, the means of lesion degree were: In the group A, 3.5; Group B, 1.2; Group C, 1. The difference between group A with the groups B and C was considered statistically significant (P < 0.05).Conclusion: Ischemic pre-and postconditioning were capable of minimizing -in a similar intensity -the tissue injury on the intestinal mucosa of rats undergone mesenteric ischemia and reperfusion process. Resumo Objetivo: Avaliar o efeito do pré e pós-condicionamento isquêmico sobre a lesão tecidual na mucosa intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica. DescriptorsMétodos: Foram estudados 30 ratos Wistar, distribuídos em três grupos: grupo A, em que se realizou isquemia (30 minutos) e reperfusão (60 minutos) mesentérica; grupo B, isquemia e reperfusão mesentérica precedidos pelo pré-condicionamento isquêmico por três ciclos de isquemia e reperfusão com duração de dois minutos cada; grupo C, isquemia e reperfusão mesentérica e, precedendo o início da reperfusão, foi realizado o pós-condicionamento isquêmico por três ciclos de reperfusão e isquemia com duração de dois minutos cada. Ao final, ressecouse um segmento do intestino delgado para análise histológica. Avaliaram-se os resultados pela classificação de Chiu et al. e procedeu-se ao tratamento estatístico.Resultados: As médias dos graus de lesão tecidual segundo a classificação de Chiu et al. foram: no grupo A, 3,5; grupo B, 1,2; grupo C, 1. A diferença entre o resultado do grupo A com os resultados dos grupos B e C foi considerada estatisticamente significativa (P < 0,05).Conclusão: O pré e pós-condicionamento isquêmico foram capazes de minimizar, com intensidade semelhante, a lesão tecidual na mucosa intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica.Descritores: Isquemia. Traumatismo por reperfusão. Precondicionamento isquêmico.

Too short cycles of postconditioning have no protective effect against reperfusion injury. Experimental study in rats.

“…The protective mechanism of IPo in ischemia and reperfusion process is still not entirely clear, but there is evidence that IPo may be related to a significant decrease in the levels of malondialdehyde and products related to lipid peroxidation. These observations suggest a reduction in the production of ROS and less injury mediated by oxidants with IPo [ 1 - 9 ] .…”

“…Several published experiments analyzed the effects of IPo in other organs and tissues, among them we can mention Darling et al [ 7 ] in which the IPo was able to minimize the area of myocardial infarction in rabbits; Tang et al [ 8 ] demonstrated the effectiveness of IPo in the prevention of coronary lesions resulting from the ischemia and reperfusion in rats, since the ischemia time did not exceed 45 minutes; Huang et al [ 3 ] have shown that the IPo was preventing tissue damage in the spinal cord of rats subjected to ischemia and reperfusion; Santos et al [ 9 ] showed that the ICRP and IPo was able to minimize tissue injury in the intestinal mucosa of rats undergoing ischemia and reperfusion process.…”

Effect of remote ischemic postconditioning inflammatory changes in the lung parenchyma of rats submitted to ischemia and reperfusion

“…In the last decade, there have been studies demonstrating the efficacy of ischemic post-conditioning in various organs when subjected to ischemia and reperfusion [ 4 ] . Clearly, then came the questions about its protective effect also at a distance, the remote ischemic postconditioning (R-IPo).…”

Evaluation of pulmonary reperfusion injury in rats subjected to mesenteric ischemia and reperfusion and protective effect of postconditioning on this process

“…Huang et al [ 3 ] demonstrated that IPC were preventing tissue damage in the spinal cord of rats subjected to I/R. Santos et al [ 8 ] showed that the ischemic preconditioning and IPC were able to minimize the tissue injury in the intestines of rats subjected to mesenteric I/R process.…”