早期肠内营养对大鼠急性坏死性胰腺炎TLR4信号通路的作用

Effect of early enteral nutrition on TLR4 signaling pathway in rats with acute necrotizing pancreatitis

目的探讨早期肠内营养对急性坏死性胰腺炎（ANP）大鼠肠黏膜TLR4信号通路的作用及机制。方法将60只SD大鼠按数字表法随机分成对照组、肠外营养组（TPN组）、肠内营养组（EEN组）。造模后1d检测血清淀粉酶活性。肠外营养、肠内营养持续给予5d后处死大鼠，取血、胰腺及结肠组织。采用ELISA法检测血清IL-6、TNF—α水平；HE染色观察胰腺病理改变；蛋白质印迹法检测大鼠结肠组织TLR4NF—KB表达。结果对照组、TPN组、EEN组大鼠造模后5d的死亡率分别为0、50％、25％；血清淀粉酶活性分别为（744±41）、（3278±219）、（2227±169）U／L；TNF-α水平为（81．57±18．25）、（465．72±42．47）、（223．21±29．94）ng／L；IL-6为（362．83±41．32）、（932．46±57．21）、（628．62±142．24）ng／L；胰腺病理评分为（0．91±0．15）、（11．1±0．61）、（6．9±0．62）分；结肠组织TLR4蛋白表达量为0．7506±0．003、1．3404±0．004、0．9544±0．004；NF—KB蛋白表达量为1．33±0．50、6．92±1．06、2．93±0．89。TPN组、EEN组均显著高于对照组，EEN组又显著低于TPN组，差异均有统计学意义（P值均〈0．05）。结论早期肠内营养能抑制ANP大鼠肠道TLR4及NF．KB信号通路，下调血清TNF-α、IL-6水平，减轻胰腺炎症反应，降低死亡率。

Objective To investigate the role of early enteral nutrition on TLR4 signaling pathway in rats with acute necrotizing pancreatitis （ ANP ）. Methods Sixty SD rats were randomly divided into three groups： sham operation group （SO group ）, total parenteral nutrition group （TPN）, early enteral nutrition group （EEN）. One day after ANP model induction, the serum level of amylase was measured. Nutrient solution was given for five days, then the rats were sacrificed, and the blood, pancreas and colon tissue were collected. The serum levels of IL-6, TNF-α were detected by ELISA. Pathologic changes of pancreas were observed by HE staining. The intestinal TLR4, NF-KB expression was measured by Western blot. Results Mortality rates of SO group, TPN group, EEN group were 0, 50% , 25% , respectively; the serum levels of amylase were （744 ±41 ）, （3 278 ± 219）, （2 227 ±169） U/L, respective/y; the serum levds of TNF-α were （ 81.57 ± 18.25 ） , （465.72 ±42.47 ） , （ 223.21 ± 29.94 ） ng/L, respectively ; the serum levels of IL-6 were （362.83 ±41.32）, （ 932.46 ±57.21 ）, （ 628.62 ±142.24 ） ng/L, respectively; the pancreatic pathologic scores were （0.91 ±0.15） , （11.1±0.61 ） , （6.9 ±0.62） ; the intestinal TLR4 expressions were 0. 7506 ± 0.003, 1. 3404 ± 0. 004, 0. 9544 ±0.004 ; the intestinal NF-KB expressions were 1.33 ±0.50, 6.92± 1.06,2.93 ± 0.89. The values of TPN and EEN group were significantly higher than those of SO group （ P 〈 0.05 ）. The values of EEN group were significantly lower than those of TPN group （P 〈 0.05）. Conclusions EEN can inhibit TLR4 and NF-KB signal pathway in gut, then reduce IL-6 and TNF-α expression and relieve inflammatory reaction of ANP, finally decrease the mortality of ANP.