谷氨酰胺强化肠内营养对炎症性肠病大鼠免疫功能的调节作用

Effects of glutamine supplementation with enteral nutrition on immune function in rats with inflammatory bowel disease

目的 研究谷氨酰胺强化肠内营养对炎症性肠病(IBD)大鼠Th17细胞的影响和对肿瘤坏死因子α(TNF-α)分泌的调节作用。方法 以100 mg/kg剂量将2,4,6-三硝基苯磺酸(TNBS)的乙醇溶液(质量比50%)一次性结肠灌注0.5 mL来构建IBD大鼠模型。40只SPF级SD雄性大鼠分为正常组、模型组、对照组、实验组,每组10只。正常组、模型组以基础饲料喂养;对照组大鼠以基础饲料添加100 mL/kg的百普素(短肽型的肠内营养制剂)混悬液,实验组大鼠以基础饲料添加100 mL/kg百普素以及0.5 g/kg的谷氨酰胺。干预7 d后,处死动物。试剂盒检测大鼠血清中TNF-α、IL-17F的含量;免疫组化检测结肠组织中髓过氧化物酶(MPO)的表达;流式细胞术检测各组大鼠结肠组织中Th17细胞的变化。结果 与正常组大鼠相比,模型组、对照组和实验组中的大鼠体质量增长较为缓慢(P<0.05);与模型组相比,对照组和实验组大鼠体质量增长较快(P<0.05);实验组大鼠肛周的清洁程度改善明显较对照组(P<0.05)。与正常组相比,模型组、对照组和实验组大鼠的DAI评分明显升高(P<0.05);与模型组相比,对照组和实验组的DAI评分明显降低(P<0.05);与对照组相比,实验组的DAI评分明显降低(P<0.05)。与正常组相比,模型组、对照组和实验组大鼠血清中TNF-α、IL-17F的含量、MPO的表达、Th17细胞计数明显升高(均P<0.05);与模型组相比,对照组和实验组大鼠血清中TNF-α、IL-17F含量、MPO表达、Th17细胞计数明显降低(均P<0.05);与对照组相比,实验组大鼠血清中TNF-α、IL-17F含量、MPO表达、Th17细胞计数明显降低(均P<0.05)。结论 谷氨酰胺联合肠内营养支持治疗能明显有助于改善炎症性肠病大鼠的症状,可能是通过抑制大鼠的炎性应激,调控其结肠组织的免疫应答来实现的。

Objective To study the effect of glutamine-supplemented enteral nutrition on the secretion of tumor necrosis factor-α(TNF-α)and Th17 cell in the rats with inflammatory bowel disease(IBD).Methods 0.5 mL 100 mg/kg dose 2,4,6-Trinitrobenzenesulfonic acid(TNBS)ethanol solution(mass ratio 50%)was colon perfused with 0.5 mL,one-time,to construct IBD rats model.Rats were divided into normal group,model group,experimental group and control group.The normal group and the model group were fed with basic feed;the control group rats were added 100 mL/kg of Peptisorb(short-peptide enteral nutrition preparation)suspension as the basic feed,and the experimental group rats were added 100 mL/kg of Peptisorb and 0.5g/kg glutamine as the basic feed.After 7 days of intervention,the animals were sacrificed.The kits were used to detect the content of TNF-αand interleukin-17F(IL-17F)in the serum.Immunohistochemistry was used to detect the expression of myeloperoxidase(MPO)in colon tissue.Flow cytometry was used to detect in Th17 cells of rats colon tissue.Results Compared with the normal group,the contents of TNF-αand IL-17F in the serum,the expression levels of MPO,and the cell count of Th17 in the model group,the experimental group and control group,were significantly increased(all P<0.05).Compared with the model group,the content of TNF-α,IL-17F in the serum,the expression levels of MPO,and the cell count of Th17 in the experimental group and control group were significantly decreased(all P<0.05).Compared with control group,the content of TNF-α,IL-17F in the serum,the expression levels of MPO,and the cell count of Th17 in the experimental group were significantly decreased(all P<0.05).Conclusion The glutamine combined with enteral nutrition support obviously could help to improve the symptoms of inflammatory bowel disease rats,which may be achieved by inhibiting the inflammatory stress of rats and regulating the immune response of their colon tissues.