Study On The Roles Of Glutamine In The Prevention At Neonatal Rat Model Of Necrotizing Enterocolitis

Objection:To establish necrotizing enterocolitis (NEC) model and study the impact of expression level of glutamine on interleukin-6(IL-6)、Tumor necrosis factor-α(TNF-α)、interleukin-10(IL-10) and secretory immunoglobulin A (SIgA) in the intestinal tissue of neonatal rats, In order to provide new Scientific basis and theoretical support for prevention and cure necrotizing enterocolitis (NEC).Methods:60 neonatal Wistar rats aged 2 days were divided into three groups at random,(no limit to male or female):Intervention group (A). Model group (B)、and Margin control group (C), n=20. A group were received glutamine (0.3g/kg) with intragastric gavage. once per day, for five days. A and B group were given lipopolysaccharide (LPS) (5mg/kg, treated by ultrapure water, 5mg/ml) intragastric administration on the sixth day, once per day, for thrsee days. The rats of A and B group were give formula feeding, the rats of C group lived with female mice.Five rats, selected form each group at random, were decapitated respectively at 2,6,12 and 24h after LPS intragastric administration of A and B group. Obtained duodenum inferior to rectum superior intestinal tissue, in which the ileocecal junction was stained by hematoxylinandeosin(HE) for the histological analysis, and the remains was used to measure the content of IL-6、TNF-α、IL-10 and SIgA with enzyme linked immunosorbent assay (ELISA) in homogenate of intestinal tissue. Using immunohistochemistry to detect the expression of IL-6、 TNF-α、IL-10 in newborn rat intestinal tissues of three groups.Results:1. The symptom and pathomorphology change of ileal tissue of each group The neonatal Wistar rats of B group appeared lazy gradually、messy hair, twelve of them showed abdominal bruising, six of them showed convulsions、bloody diarrhea, three of them died in the study. Atfer killed those rats, we saw that their stomach accumulated very much, the wall of their intestines and mesentery congested, intestinal canal dilated and edema, exudation increased, even spot-lamellar hemorrhage and necrosis. after H-E staining:The intestinal epithelium of B group denatured、lamina propria and submucosal separated slightly、villi glandule shed and depleted 2h later. After 6h its intestinal epithelium structure disappeared completely, the structure of villus disintegrated and separated, submucosa and lamina propria severe edema; about 12 hours later its structure began to repair but was unclear.Approximately 24h submucosal was oedematous and villus was obviously clear. C group appeared lazy, a little messy hair and abdominal distention,We saw that the intestinal canal mild dilated and edema after dissection,without hemorrhage and necrosis.According to light microscopic examination, C group had slight pathological intestinal damage compared with B group.2. The content of ileal tissue IL-6、TNF-α、IL-10 and SIgA in different neonatal Wistar rats group.The content of IL-6 in the ileal tissue in B group were significantly increased at 2,6,12and24h compared withA group (P<0.05); and its content at C group were significantly decreasedat 2,6, and12h compared with B group (P<0.05). The content of TNF-a in the ileal tissue in B group were significantly increased at 2,6,12 and 24h compared with A group (P<0.05); and its content at C group were significantly decreased at 2,6,12 and 24h compared with B group (P<0.05). The content of IL-10 in the ileal tissue in B group were significantly increased at 2,6, 12 and 24h compared with A group (P<0.05); and its content at C group were significantly increased at 12 and 24h compared with B group (P<0.05). The content of SIgA in the ileal tissue in B group were significantly decreased at 2,6,12 and 24h compared with A group (P<0.05); and its content at C group were significantly increased at 12h and 24h compared with B group (P<0.05)Conclusion:1. LPS intragastric administration combined with formula feeding could induced NEC model successful.2. In neonatal Wistar rats of necrotizing enterocolitic model,induced by LPS intragastric administration combined with formula feeding,the IL-6 and TNF-αcontent of ileal tissue were decreased obviously in treatment group(C), compared with B group, however, the IL-10 content of ileal tissue were increased obviously in treatment group(C), compared with B group.These showed that glutamine maybe protect intestinal tissue by depressing the TNF-a, IL-6 expression and promoting the expression of IL-10 in cascade reaction of inflammatory. And relieve the histopathological damage of ileum tissue in neonatal Wistar rats of necrotizing enterocolitic model.3. In neonatal Wistar rats of necrotizing enterocolitic model,induced by LPS intragastric administration combined with formula feeding, the SIgA content of ileal tissue were increased in treatment group(C) rats, Compared with B group.These showed that glutamine maybe protect intestinal tissue through secreting SIgAof intestine humoral immunity.