谷氨酰胺对坏死性小肠结肠炎新生大鼠的保护作用

Protective Effects of Glutamine on Neonatal Rats with Necrotizing Enterocolitis

目的观察坏死性小肠结肠炎(NEC)新生鼠肠道组织中Caspase-3和ki67的表达情况,探讨谷氨酰胺(Gln)对NEC新生鼠肠道的保护作用及可能机制。方法 30只早产鼠(21d)及30只足月新生鼠分别分为早产模型组、早产Gln干预组、早产对照组、足月模型组、足月Gln干预组和足月对照组。代乳品人工喂养+缺氧+冷刺激建立NEC模型,Gln干预组采用代乳品+Gln人工喂养,同时予缺氧冷刺激;对照组置于(代)母鼠身旁喂养,不进行任何干预。第3天处死后取出大鼠肠道,HE染色后对其回肠进行病理评分,免疫组织化学检测其空肠、回肠及结肠Caspase-3和ki67的表达。采用SPSS13.0软件进行统计学分析。结果与对照组比较,模型组空肠、回肠及结肠病理评分、Caspase-3和ki67的表达均增加(Pa<0.01);与模型组比较,Gln干预组上述指标的改变得到显著改善(Pa<0.05);早产鼠模型组、Gln干预组及对照组空肠、回肠、结肠病理评分、Caspase-3和ki67的表达分别与对应的足月鼠模型组、Gln干预组及对照组比较,差异均无统计学意义(Pa>0.05)。结论细胞凋亡与增殖参与了NEC的病变过程,Gln对肠道的保护作用可能是通过调控凋亡与增殖的平衡来实现的。

Objective To detect the expressions of Caspase -3 and ki67 in intestine in rats with necrotizing enterocolitis（NEC） ,and to explore the protective effect and possible regulation mechanism of glutamine （Gln） on NEC rats. Methods Thirty premature rats（21 d） and 30 full term rats were divided into 3 groups, respectively （ n = 10, each） ： control group, model group, Gin intervention group. The rats in model group were given formula feeding, hypoxia and cold stress. The Gin intervention group were added with Gln to the milk substitute, and also given artificial feeding,hypoxia plus cold stress. The rats in control group were raised by their mother or foster and did not receive any inter- vention. Sacrificed all the rats and obtained intestine tissues on the 3rd day. The histological changes of ileal tissues were scored after hematoxy- lin- eosin（HE） staining. The expressions of Caspase -3 and ki67 in jejunum, ileum and colon were detected by immunohistochemistry. SPSS 13.0 software was used to analyze the data. Results Compared with control group,the histological score and the expressions of Caspase -3 and ki67 were significantly increased （P 〈 0.01 ）. However, compared with model group,these changes were prevented in Gin intervention group （P 〈0.05）. All the indicators showed no singnificant differences between premature rats and full term rats which experienced the same treatment （P 〉 0.05）. Conclusions Apoptosis and proliferation may be involved in the process of NEC. The protective effect of Gin on in- testines may be achieved through regulating the balance of apoptosis and proliferation.