探讨核因子κB（NF-κB）在重症急性胰腺炎（SAP）大鼠肠黏膜屏障损伤中的作用机制。

24只Wastar大鼠按随机数字表法分为对照组、SAP组和NF-κB抑制剂组即二硫代氨基甲酸吡咯烷（PDTC）组，每组各8只。制作SAP大鼠模型，对照组仅翻动胰腺，PDTC组于建模后2 h经尾静脉注射PDTC溶液40 mL/kg。各组大鼠于建模后24 h处死，观察各组大鼠腹腔内大体改变，比较各组肠黏膜的病理改变、通透性的变化及肿瘤坏死因子α（TNF-α）、白细胞介素1（IL-1）的表达水平，应用免疫组织化学法检测大鼠肠黏膜上皮细胞紧密连接蛋白Occludin的表达。

对照组大鼠腹腔内无明显炎症征象，肠管无水肿充血；SAP组和PDTC组大鼠均有不同程度的腹水、肠管水肿、充血，且SAP组更为严重。光学显微镜下对照组肠黏膜未见明显损伤，SAP组和PDTC组大鼠回肠可见不同程度的肠黏膜破坏，且PDTC组较轻。三组大鼠的病理评分[（3.6 ± 1.4）、（21.3 ± 3.7）、（33.8 ± 4.2）分]和肠黏膜通透性[（22 ± 6）、（188 ± 26）、（328 ± 35）nL·min^-1·cm^-1]比较，差异均有统计学意义（F = 7.259、6.402，P均< 0.05），且SAP组肠黏膜通透性较PDTC组增加更为显著（P < 0.05）。三组大鼠TNF-α[（146 ± 37）、（1 684 ± 80）、（2 896 ± 99）ng/L]，IL-1 [（53 ± 10）、（1 756 ± 60）、（2 893 ± 88）ng/L]表达水平比较，差异均有统计学意义（F = 5.751、7.247，P均< 0.05），其中SAP组和PDTC组肠道TNF-α、IL-1表达水平均较对照组显著增加（P均< 0.05），且SAP组大鼠TNF-α和IL-1表达水平均较PDTC组更高（P均< 0.05）。免疫组织化学结果显示，对照组Occludin蛋白沿肠黏膜上皮细胞分布，呈很强的棕褐色线状信号；PDTC组Occludin的定位与对照组没有明显区别，但棕褐色阳性信号有所减弱；SAP组阳性细胞明显减少。三组大鼠Occludin[（15.6 ± 3.0）、（6.4 ± 1.4）、（3.1 ± 1.2）]表达水平比较，差异有统计学意义（F = 5.427，P < 0.05）。

SAP大鼠肠黏膜屏障损伤可能与肠组织中NF-κB表达升高有关，从而下调肠上皮细胞紧密连接蛋白Occludin的表达，抑制NF-κB表达对SAP肠黏膜屏障损伤具有保护作用。

To investigate the role of the nuclear factor-kappa B (NF-κB) in intestinal mucosal barrier injury in rats with severe acute pancreatitis (SAP).

A total of 24 Wastar rats were divided into the control group, the SAP group and the NF-κB inhibitor group [i.e. the pyrrolidine dithiocarbamate (PDTC) group] according to the random number table method, 8 rats in each group. The SAP rat models were made, rats in the control group were only turned the pancreas, and rats in the PDTC group were injected with 40 mL/kg PDTC solution through tail veins after modeling for 2 h. Rats in each group were sacrificed after modeling for 24 h. Then the gross changes in the abdominal cavity of rats in each group were observed; the pathological changes of the intestinal mucosa, the change of permeability, and the expressions of tumor necrosis factor-alpha (TNF-α) and interleukin 1 (IL-1) were compared. The expression of Occludin in intestinal mucosal epithelial cells of rats was detected by the immunohistochemical method.

There was no obvious inflammation in the abdominal cavity and no edema and hyperemia in the intestinal tract of rats in the control group, while the rats in SAP and PDTC groups had different degrees of ascites, intestinal edema and hyperemia, and rats in the SAP group were more serious. No obvious damage can be seen in the intestinal mucosa in the control group under the optical microscope, while different degrees of intestinal mucosal damage were observed in the ileum of rats in the SAP and PDTC groups, and the PDTC group was lighter. The pathological scores [(3.6 ± 1.4), (21.3 ± 3.7), (33.8 ± 4.2)] and the intestinal mucosal permeability [(22 ± 6), (188 ± 26), (328 ± 35) nL·min^-1·cm^-1] were significantly different in these three groups (F = 7.259, 6.402; both P < 0.05). The permeability of intestinal mucosa in the SAP group increased more markedly as compared to the PDTC group (P < 0.05). The expressions of TNF-α [(146 + 37), (1 684 + 80), (2 896 + 99) ng/L] and IL-1 [(53 ± 10), (1 756 ± 60), (2 893± 88) ng/L] in these three groups both showed statistical significance (F = 5.751, 7.247; both P < 0.05). The expressions of TNF-α and IL-1 in the intestinal tract in SAP and PDTC groups were significantly higher than those in the control group (all P < 0.05), and the expressions of TNF-α and IL-1 were higher in the SAP group than in the PDTC group (all P < 0.05). The immunohistochemical results showed that the Occludin proteins in the control group were distributed along the epithelial cells of the intestinal mucosa and showed a strong brown linear signal. The localization of Occludin in the PDTC group was not significantly different from that in the control group, but the positive brown signal was weakened, and the positive cells decreased significantly in the SAP group. There was significant difference of Occludin expressions [(15.6 ± 3.0), (6.4 ± 1.4), (3.1 ± 1.2)] in these three groups (F = 5.427, P < 0.05).

The intestinal mucosal barrier damage in SAP rats may be related to the increase of the NF-κB expression in intestinal tissues, thus down-regulation of the Occludin expression in intestinal epithelial cells and the inhibition of the NF-κB expression would have a protective effect on the intestinal mucosal barrier of SAP.