Acta Cirúrgica Brasileira (Apr 2006)

Avaliação de um modelo experimental de enterocolite necrosante neonatal em ratos Evaluation of an experimental model of necrotizing enterocolitis in rats

  • Karine Furtado Meyer,
  • José Luiz Martins,
  • Luiz Gonzaga de Freitas Filho,
  • Maria Luiza Vilela Oliva,
  • Francy Reis da Silva Patrício,
  • Maurício Macedo,
  • Lina Wang

DOI
https://doi.org/10.1590/S0102-86502006000200011
Journal volume & issue
Vol. 21, no. 2
pp. 113 – 118

Abstract

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OBJETIVO: Avaliar um modelo experimental de enterocolite necrosante em ratos proposto por Okur e colaboradores em 1995. MÉTODOS: Utilizou-se 28 ratos da raça EPM-Wistar no primeiro dia de vida, com peso entre 4 a 6 gramas. Os animais foram submetidos a hipóxia (H) colocando os filhotes em uma câmara de gás CO2 para sacrifício de roedores onde receberam um fluxo de ar contendo 100% de CO2 durante 5 minutos. Após a hipóxia os animais foram reanimados (R) com fluxo de ar contendo O2 a 100%, também durante 5 minutos. Os animais divididos em dois grupos: G1: controle (n=12): ratos não submetidos a H-R; G2: (n=16): ratos submetidos a H-R. Segmentos de intestino delgado e cólon foram preparados para análise histológica. O restante do intestino foi utilizado para dosagem de malondialdeído tecidual. RESULTADOS: Dosagem de malondialdeído do G1 foi em média 1,05 (0,44-2,03) e do G2 foi em média 2,60 (0,59- 6,4) nmol MDA/mg proteína. O G2 teve média significativamente maior do que a do grupo controle (pOBJECTIVE: To evaluate an experimental model of necrotizing enterocolitis in rats proposed by OKUR e col. in 1995. METHODS: On their first day of life, 28 EPM-Wistar rats weighing between 4 and 6 grams were submitted to hypoxia (H) by placing them in a CO2 gas chamber for rodents' sacrifice, where they received a 100% CO2 air flow for 5 minutes. After the hypoxia the animals were reanimated (R) with a 100% O2 air flow, also for 5 minutes. The animals were allocated in two groups: G1: control (n=12): rats not submitted to H-R; G2: (n=16): rats submitted to H-R. Segments of the small intestine and colon were prepared for histological analysis. The remaining intestine was used to measure tissular malondialdehyde. RESULTS: Mean malondialdehyde dosages were 1.05 (0.44-2.03) and 2.60 (0.59- 6.4) nmol MDA/mg protein for G1 and G2, respectively. G2's mean value was significantly higher than in the control group (p<0.002). Significant statistical difference between the studied groups was found in relation the level of injury, with G1 presenting significantly lower levels than G2. CONCLUSIONS: The model showed that neonatal hypoxia may cause intestinal wall injury in rats. Despite the discreet histological injuries found, the method is suitable for evaluation of tissular free radicals.

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