The ischemic preconditioning and postconditioning effect on the intestinal mucosa of rats undergoing mesenteric ischemia/reperfusion procedure

Abstract

Purpose:To evaluate the effect of the ischemic preconditioning and the ischemic postconditioning over the tissue injury in the intestinal mucosa of rats undergoing the procedure of mesenteric ischemia and reperfusion. Methods: Thirty Wistar rats were studied, divided in three groups: group A, undergoing mesenteric ischemia (30 minutes) and reperfusion (60 minutes); group B, mesenteric ischemia and reperfusion preceded by ischemic preconditioning; group C, mesenteric ischemia and reperfusion and, before the beginning of reperfusion, the ischemic postconditioning was performed. At the end, a segment of the small intestine was dissected for histological analysis. The results were evaluated using the CHIU et al. 6 classification followed by the statistic treatment. Results: The mean values of the tissue injury levels were: group A, 3.5; group B, 1.2; and group C, 1. The difference between the result of group A with the results of groups B and C was considered statistically significant (p < 0,05). Conclusion: The ischemic preconditioning and postconditioning are able to minimize the tissue injury in the intestines of rats that underwent the procedure of mesenteric ischemia and reperfusion. Key words: Ischemia. Reperfusion. Ischemic Preconditioning. Rats. 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. Métodos: 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; grupo C, isquemia e reperfusão mesentérica e, precedendo o início da reperfusão, foi realizado o pós-condicionamento isquêmico. Ao final, ressecou-se um segmento do intestino delgado para análise histológica. Avaliaram-se os resultados pela classificação de CHIU e col. 6 e procedeu-se o tratamento estatístico. Resultados: As médias dos graus de lesão tecidual foram: 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 a lesão tecidual na mucosa intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica. Descritores: Isquemia. Reperfusão. Precondicionamento Isquêmico. Ratos.

Postconditioning effect in the hepatic ischemia and reperfusion in rats

“…As has been demonstrated in situations of intestinal ischemia and reperfusion 12 , renal 13 , cerebral 9 and spinal cord 11 , also in the liver of rats we can see the capacity of IPo of to minimize the damage resulting of this process.…”

“…This method was used successfully in myocardial 7 , brain 9 , kidney 10 , spinal cord 11 , intestine 12 and, recently, just one study that demonstrate its efficacy in liver 13 ischemia and reperfusion, which justifies this study.…”

Pré-condicionamento isquêmico em diferentes tempos e seu efeito na translocação bacteriana induzida por isquemia e reperfusão intestinal em ratos

“…Santos et al 11 compared the effects of these two mechanisms by submitting their samples to three cycles of ischemia and reperfusion, two minutes each. The preconditioning preceded ischemia, which was followed by reperfusion, and in another group ischemia was caused, then postconditioning and posteriorly reperfusion.…”

“…Based on the fact that ischemic preconditioning attenuates the tissue injury caused by ischemia-reperfusion, Aksoyek et al 10 demonstrated in an experimental model, in which rats were subjected to ischemic preconditioning ten minutes prior to sustained ischemia, that BT was lower than in those animals that had not undergone preconditioning. Although most reports in the literature using the time of ten minutes in ischemic preconditioning of the small intestine of rats, the optimal protocol of intestinal preconditioning in these animals, including the short ischemia time, is not yet well established 5,11 . The damage to the intestinal mucosal barrier can induce bacterial translocation, the gastrointestinal tract having been defined as the "motor" of multiple organ failure.…”

The Role of Hypoxia-Induced Factor-1 (Hif-1) in Cytoprotection Effect in Ischemic and Pharmacologic Postconditioning

“…Было установлено, что 3 эпизода ишемии по 30 секунд, разделенные 30-секундными эпизодами реперфузии, при выполнении непосред-ственно после 60-минутной ишемии позволяют уменьшить степень необратимого повреждения мио-карда [4]. Позднее протективный эффект ИПостК был описан и при воспроизведении ишемии-репер-фузии других органов, включая головной и спинной мозг, печень, почку, легкое, тонкую кишку [1, 3,[5][6][7]. При дальнейшем изучении феномена ИПостК было показано, что цитопротективным действием обла-дают ишемические стимулы различной кратности и длительности, выполненные в разные сроки после прекращения тестовой (пролонгированной) ишемии.…”