重组肠三叶因子对急性坏死性胰腺炎大鼠肠黏膜保护作用的研究

Effect of recombinant intestinal trefoil factor on intestinal mucosa of acute necrotizing pancreatitis in rats

目的探讨重组肠三叶因子（rITF）对急性坏死性胰腺炎（ANP）大鼠肠黏膜的保护作用及其机制。方法SD雄性大鼠60只，按随机数字表法分为对照组、ANP组、rITF组，每组20只。逆行胰胆管注射5％牛黄胆酸钠100ul／100g体重制备ANP模型。rITF组制模前后尾静脉注射rITF0．5mg／100g体重，对照组及ANP组注射等量生理盐水，术后12、24h分批处死大鼠。取血检测淀粉酶含量，取末端回肠组织观察病理学改变并予评分、免疫组化法检测肠黏膜NF-KB活性，RT-PCR法检测肠黏膜TNF—α mRNA、ICAM-1 mRNA的表达。结果ANP组和rITF组血淀粉酶水平较同时点对照组均显著升高。ANP组肠黏膜损伤评分较同时点对照组高（P〈0．05）；ANP12h组较rITF12h组高（P〈0．05），但24h组间评分无明显差异。对照组、ANP组与rITF组12h肠黏膜NF—kB阳性细胞数分别为（26±4）个、（55±8）个、（49±4）个；回肠组织TNF—α mRNA相对表达量分别为0．050±0．005、1．040±0．031和0．792±0．0256；回肠组织ICAM-1 mRNA相对表达量分别为0．045±0．010、0．795±0．037和0．400±0．031。ANP组上述各项指标值均较对照组显著增加（P〈0．05或P〈0．01），而rITF组又较ANP组均显著减少（P〈0．05）。结论重组肠三叶因子对ANP大鼠肠黏膜具有保护作用，其机制可能通过抑制肠黏膜NF-kB活化，下调TNF—α mRNA、ICAM-1 mRNA表达.

Objective To investigate the effect of recombinant intestinal trefoil factor （rlTF） on the intestinal mueosa of acute necrotizing pancreatitis （ANP） rats and explore the mechanism. Methods 60 male SD rats were randomly divided into control group （ n = 20） , ANP group （ n = 20） , rITF group （ n = 20）. ANP was induced by retrograde injection of 5% sodium taurocholate （100 ul/100 g） into biliopancreatic duct. Rats in rITF group were injected with rITF （0.5 mg/100 g） before and after ANP induction. The rats in ANP group and control group received same amount of normal saline. Each group were sacrificed 12 h or 24 h later, respectively. Blood sample was taken to determine the serum level of amylase. Terminal ileum was resected to observe the pathologic changes; immunohistochemistry method was applied to detect the activity of NF-kB; the expression of TNF-α mRNA, ICAM-1 mRNA in intestinal mucosa was measured by RT-PCR. Results Intestinal injury score of ANP group was higher than that of control group （P 〈 0.05 ）, intestinal injury score of ANP 12 h group was higher than that of rlTF 12 h group （P 〈 0.05 ）, but there was no significant difference between ANP 24 h group and rITF 24 h group. The number of positive NF-KB cells was 26±4, 55 ±8, 49 ±4,respectively; the relatively expression of TNF-α mRNA in terminal ileum was 0.050 ± 0. 005, 1. 040 ± 0.031 and 0.792 ±0. 0256, respectively; the relatively expression of ICAM-1 mRNA was 0. 045 ±0. 010, 0. 795 ± 0. 037 and 0. 400 ±0. 031, respectively, in control group, ANP group and rITF 12 h group. The corresponding values in the ANP group were significantly increased compared with those values in the control group （ P 〈 0.05 or P 〈 O. 01 ）. Conclusions rITF may protect the intestinal mucosa, the mechanism may include inhibit NF-kB activation, down-regulate TNF-α mRNA, ICAM-1 mRNA expression.