[TNBS诱导的溃疡性结肠炎大鼠肥大细胞和肠道激素的变化]

[Changes of mast cells and gut hormones in rats with TNBS-induced ulcerative colitis].

作者信息

Zhao Ping, Dong Lei, Luo Jin-Yan, Guan Hai-Tao, Ma Hui, Wang Xue-Qin

机构信息

Department of Gastroenterology, Second Affiliated Hospital, Xi'an Jiaotong University College of Medicine, Xi'an 710004, China.

出版信息

Nan Fang Yi Ke Da Xue Xue Bao. 2009 Jul;29(7):1359-63.

PMID:19620053

Abstract

OBJECTIVE

To investigate the role of mast cells and gut hormones and their interactions in TNBS-induced ulcerative colitis.

METHODS

Rat models of ulcerative colitis were established by a single intracolonic injection of 100 mg/kg TNBS (in 0.3 ml 50% ethanol). At 0, 6, 11, 16, 21 days after TNBS injection, the rats were sacrificed to determine the count of the mast cells. Histamine level in the whole blood, and the levels of histamine, substance P (SP), vasoactive intestinal peptide (VIP), and somatostatin (SS) in the distal colons were measured by fluorimetry or radioimmune assay. Immunofluorescence double staining was used to observe the relationship of the mast cells with SP, VIP, and SS positive nerve fibers.

RESULTS

On day 6 after TNBS injection, obvious ulcers occurred in the distal colon of the rats with significantly increased histamine level in the whole blood (P<0.05) but significantly decreased colonic histamine levels (P<0.05). The histamine levels in the whole blood and distal colon gradually recovered the normal levels. The mast cells significantly increased on day 16 (P<0.05) and maintained the high level till day 21. The distribution of mast cells was altered after TNBS injection, and the cells were found to aggregate in the myenteric region. SP levels in the distal colon significantly increased on day 11 (P<0.05) and maintained the high level till day 21. Immunofluorescence double staining revealed numerous mast cells close to the SP- and VIP-positive nerve fibers at different time points after TNBS injection. VIP positivity and the number of VIP-positive nerve fibers in the myenteric region were markedly increased, but no mast cells were observed in association with SP- and VIP-positive nerve fibers. The distribution of MC was not found to associate with the SS-positive nerve fibers.

CONCLUSION

The mast cells and histamine released by them, as well as parasecretion of SP and VIP, participate in tissue damage by TNBS-induced colitis. Bidirectional neuroimmunomodulation of the mast cells, SP and VIP have important effect on the development of TNBS-induced colitis.

摘要

目的

探讨肥大细胞和肠道激素在三硝基苯磺酸（TNBS）诱导的溃疡性结肠炎中的作用及其相互作用。

方法

通过在结肠内单次注射100mg/kg TNBS（溶于0.3ml 50%乙醇中）建立溃疡性结肠炎大鼠模型。在注射TNBS后的0、6、11、16、21天，处死大鼠以测定肥大细胞计数。采用荧光法或放射免疫分析法测定全血组胺水平以及远端结肠中组胺、P物质（SP）、血管活性肠肽（VIP）和生长抑素（SS）的水平。采用免疫荧光双染色法观察肥大细胞与SP、VIP和SS阳性神经纤维的关系。

结果

注射TNBS后第6天，大鼠远端结肠出现明显溃疡，全血组胺水平显著升高（P<0.05），但结肠组胺水平显著降低（P<0.05）。全血和远端结肠中的组胺水平逐渐恢复至正常水平。肥大细胞在第16天显著增加（P<0.05），并维持高水平直至第21天。TNBS注射后肥大细胞分布发生改变，发现细胞聚集在肌间区域。远端结肠中SP水平在第11天显著升高（P<0.05），并维持高水平直至第21天。免疫荧光双染色显示，在注射TNBS后的不同时间点，许多肥大细胞靠近SP和VIP阳性神经纤维。肌间区域VIP阳性率和VIP阳性神经纤维数量明显增加，但未观察到与SP和VIP阳性神经纤维相关的肥大细胞。未发现肥大细胞的分布与SS阳性神经纤维有关。