Comparative study of the hyperbaric hyperoxygenation in ischemic colonic loops in rats

Abstract

Comparative study of the hyperbaric hyperoxygenation in ischemic colonic loops in rats -ORIGINAL ARTICLE Comparative study of the hyperbaric hyperoxygenation in ischemic colonic loops in rats 1Estudo comparativo da hiperoxigenação hiperbárica em alças cólicas isquêmicas em ratos ABSTRACT Purpose: To analyze and to evaluate the effect of the hyperbaric hyperoxygenation in the mechanical resistance of ischemic colon of rats. Methods: Eighty rats, distributed in four groups of 20 animals in each one, were used. In group 1 (G1), the control group, ischemia was not caused. Group 2 was submitted to the lesser degree of ischemia. Group 3 was submitted to the intermediate degree of ischemia. In group 4, a bigger degree of intestinal ischemia was provoked. Each group was divided in two sub-groups of ten animals each: with hyperbaric chamber (CC) and without hyperbaric chamber (SC). The animals of the four CC subgroups were placed in an experimental hyperbaric chamber in order to inhale oxygen at 100%, at two Absolute Atmospheres, for 120 minutes, for a four-day consecutive period. The animals of the four SC subgroups were kept in environment air during the five days of the experiment. All animals have been submitted to the mechanical study of the intestinal loop by the pressure test of the rupture by liquid distension. The euthanasia occurred in the fifth post-operative day. Results: Considering the ischemia factor, the four groups were different among them (p=0.0001). There was no statistical difference between subgroups CC and SC (p=0.3461). Conclusion: The hyperbaric oxygen-therapy did not present improvement on the induced ischemia in rats upright colic loop. Key words: Ischemia. Colon. Hyperbaric oxygenation. Rats. RESUMOObjetivo: Analisar e avaliar os efeitos da hiperoxigenação hiperbárica na resistência mecânica do cólon isquêmico de ratos. Métodos: Foram utilizados 80 ratos distribuídos em quatro grupos de 20 animais. No grupo 1, grupo controle, não se provocou isquemia. O grupo 2 foi submetido ao grau menor de isquemia. O grupo 3 foi submetido ao grau intermediário de isquemia. No grupo 4, provocou-se grau maior de isquemia intestinal. Cada grupo foi dividido em dois subgrupos de dez animais cada: com câmara hiperbárica (CC) e sem câmara hiperbárica (SC). Os animais dos quatro subgrupos CC foram colocados em uma câmara hiperbárica experimental para inalarem oxigênio a 100%, a duas atmosferas absolutas, durante 120 minutos, por quatro dias consecutivos. Os animais dos quatro subgrupos SC foram mantidos somente em ar ambiente. Todos animais foram submetidos ao estudo mecânico da alça intestinal pelo teste de pressão de ruptura pela distensão por líquido. A eutanásia ocorreu no quinto dia pós-operatório. Resultados: Os quatro grupos são diferentes entre si considerando o fator isquemia (p= 0.0001). Não houve diferença estatística entre os subgrupos CC e SC (p= 0.3461). Conclusão: A oxigenoterapia hiperbárica não apresentou melhora sobre a isquemia induzida em alça cólica íntegra de ratos. Descritores: Isquemia. Cól...

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“…Rocha et al 40 , showed that HBO does not improve the pression of explosion in rats colic laps with progressive levels of ischemia.…”

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Responses of matrix metalloproteinases to hyperbaric oxygen treatment: changing for good or ill?

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