Evaluation of an experimental model of necrotizing enterocolitis in rats

OBJECTIVE: 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.

Enterocolitis, Necrotizing; Models, Animal; Rats

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