谷氨酰胺对新生大鼠坏死性小肠结肠炎肠道组织血管内皮生长因子表达的影响

The effect of glutamine on the expression of vascular endothelial growth factor in intestinal tissue of neonatal rats with necrotizing enterocolitis

目的探讨谷氨酰胺（Gln）对新生大鼠坏死性小肠结肠炎（NEC）肠道组织血管内皮生长因子（VEGF）表达的影响,了解Gln对肠黏膜的保护作用。方法新生SD大鼠48只随机分为空白对照组、Gln对照组、NEC模型组、NEC＋Gln组,每组12只。空白对照组予鼠乳代乳品人工喂养3天;Gln对照组采用鼠乳代乳品喂养,每日1次Gln,0.3 g/（kg·d）,连续3天;NEC模型组采用鼠乳代乳品喂养＋缺氧＋冷刺激,连续3天建立NEC模型;NEC＋Gln组在建立NEC模型的同时,每日给予1次Gln,0.3 g/（kg·d）,连续3天。采用免疫组织化学方法检测各组大鼠肠道组织VEGF的表达。结果肠道组织VEGF表达指数由高到低依次为NEC模型组、NEC＋Gln组、空白对照组及Gln对照组[77.35（68.70~86.00）%、23.83（19.49~28.17）%、18.92（15.55~22.29）%、16.92（13.77~20.07）%],NEC模型组高于NEC＋Gln组、空白对照组和Gln对照组,NEC＋Gln组高于Gln对照组,差异有统计学意义（P〈0.008 3）;空白对照组和NEC＋Gln组、Gln组比较差异无统计学意义（P〉0.008 3）。结论外源性Gln可能通过下调VEGF表达、抑制病理性新生血管生成,减轻炎症反应,对NEC肠道起保护作用。

Objective To study the effect of glutamine （Gln）on the expression of vascular endothelial growth factor （VEGF） in intestinal tissue of neonatal rats with necrotizing enteroeolitis （NEC） ,and the protective effect of Gin on intestinal mucosa. Methods Total of 48 neonatal rats were randomly assigned into 4 groups ： control group, Gln group, NEC group, NEC ＋ Gln group, with 12 rats in each group. Rats in the control group were fed with rat milk substitutes for 3 days. Gln group with rat milk substitutes mixed with Gln [0. 3g/（kg.d） once a day] for 3 days. NEC group with rat milk substitutes and hypoxic-reoxygen-cold exposure twice a day for 3 days. NEC ＋Gln group with rat milk substitutes mixed with Gln [0. 3g/（kg.d） once a day] and hypoxic-reoxygen-cold exposure twice a day for 3 days. The expression of VEGF were determined using immunohistochemical （IHC） analysis. Results The index of VEGF expression in intestinal tissue from highest to lowest were NEC group, NEC ＋Gln group, control group and Gln group [ 77.35 （ 68.70 - 86.00 ） %, 23.83 （ 19.49 - 28. 17 ） %,18.92（ 15.55 -22. 29） %, 16.92（ 13.77 - 20. 07 ） % ]. The index of VEGF expression in NEC group was significantly higher than NEC ＋ Gln group, control group and Gin group. The control group, NEC ＋ Gln group and Gin group had no statistically significant differences. Conclusions The exogenous Gin may down-regulate VEGF expression in neonatal rat intestinal mucosa to inhibit the pathological neovascularization and relieve inflammation to protect the intestines of NEC.