The principles of preparing neonatal rat necrotizing enterocolitis model

  Objective: To clarify a simple and effective NEC modeling method by improving and comparing the methods for establishing necrotizing enterocolitis animal models commonly used at home and abroad.

  Method: Use newborn SD rats within 2 hours and divide them into 5 groups randomly. There are 10 in the control group and 20 in each group in the experimental group. Breastfeeding group A and surrogate rats in the same cage without intervention; group B artificial feeding + hypoxic cold stimulation + (lipopolysaccharide) LPS forced feeding (5 mg/kg body weight); group C artificial feeding + low oxygen . Cold stimulation + LPS forced feeding (10 mg/kg); D group artificial nutrition + hypoxic cold stimulation + LPS intraperitoneal injection (2 mg/kg); E group artificial nutrition + hypoxia cold stimulation + LPS intraperitoneal injection (5 mg/kg) ). Observe the daily activities and weight changes of newborn rats. After the experiment, in order to assess the degree of pathological damage to the small intestine, the small intestine tissue was collected for hematoxylin-eosin staining, and the level of tumor necrosis factor alpha (TNF-α) in the small intestine tissue was detected.

  Result: The newborn rats in the experimental group showed various degrees of hypofunction, abdominal distension, diarrhea, black stool and weight loss. The pathological score showed that the pathological damage score of the experimental group was significantly higher than that of the control group (P\u003c0.05). The incidence of NEC in the LPS intraperitoneal injection group (D, E) was higher than that in the oral administration group (B, C) (P\u003c0.05), but the LPS high-dose (5 mg/kg) intraperitoneal injection group was even more so. The non-NEC-related mortality was significantly higher than this group (P\u003c0.05).

  Conclusion: The method of establishing NEC is more flexible and stable by combining artificial feeding and hypoxic hypothermia stimulation with low-dose LPS (2 mg/kg) intraperitoneal injection.