内脏高敏感大鼠肠道5-羟色胺转运体的变化以及中药肠吉安治疗的研究

目前认为肠易激综合征（IBS）的主要病理机制之一是内脏高敏感，5-羟色胺（5-HT）在内脏高敏感的发生中起重要作用，而5-HT主要通过5-HT转运体（SERT）调节。目的：研究内脏高敏感大鼠结肠黏膜5-HT和SERT的表达，并评估中药肠吉安对内脏高敏感的疗效。方法：18只Sprague-Dawley新生大鼠随机分为对照组、模型组、肠吉安治疗组，后两组制备内脏高敏感模型。对照组和模型组予0．9％NaCl溶液，肠吉安治疗组予0．9％NaCl溶液和中药肠吉安。比较各组腹壁回撤反射（AWR）评分，并取结肠组织行5．HT、SERT免疫组化染色。结果：与对照组相比，在10、20和40mmHg（1mm Hg=0．133kPa）压力结直肠扩张时，模型组大鼠AWR评分显著升高（P〈0.05），结肠黏膜5-HT表达显著增高（P〈0．05），SERT表达则降低（P〈0．05）。肠吉安治疗后，在较低压力下，AWR评分较模型组显著降低（P〈0．05），5-HT表达显著降低（P〈0．05），SERT表达则显著升高（P〈0．05）。结论：肠道SERT表达降低导致5-HT表达增高，可能是IBS大鼠内脏高敏感的重要机制之一，中药肠吉安可使两者在肠道的表达趋向正常，从而改善大鼠内脏高敏感。

Study on Changes of Colorectal Serotonin Transporter in Rats with Visceral Hypersensitivity and Treatment with Traditional Chinese Medicine Changji''''an

Visceral hypersensitivity is one of the most important pathological mechanisms of irritable bowel syndrome （IBS）, and 5-hydroxytryptamine （5-HT） regulated mainly by serotonin transporter （SERT） plays an important role in the development of visceral hypersensitivity. Aims： To study the expressions of 5-HT and SERT in colonic mucosa of rats with visceral hypersensitivity, and to evaluate the therapeutic effect of traditional Chinese medicine Changji＇an （CJA） on visceral hypersensitivity. Methods： Eighteen neonatal Sprague-Dawley rats were randomly divided into 3 groups： control group, model group, and CJA-treated group. Visceral hypersensitivity model was constructed in model group and CJA-treated group. Control group and model group were given 0.9% NaC1 solution, and CJA-treated group were administrated with 0.9% NaC1 solution and CJA. Abdominal withdrawal reflex （AWR） score was determined, and expressions of 5-HT and SERT in colon were detected by immunohistochemistry. Results： Compared with control group, AWR score at colon distention pressure 10, 20 and 40 mm Hg （1 mm Hg=0.133 kPa） were significandy higher and expression of 5-HT increased markedly in model group （P〈0.05）, whereas SERT expression decreased obviously （P〈0.05）. After treatment with CJA, at lower distention pressure AWR score and expression of 5-HT decreased markedly than those in model group （P〈0.05）, expression of SERT increased significantly （P〈0.05）. Conclusions： Lowering expression of SERT may result in increasing expression of 5-HT, which may be one of the pathogenesis of visceral hypersensitivity in IBS, and traditional Chinese medicine CJA has therapeutic effect by normalizing the expressions of 5-HT and SERT, and ameliorate visceral hypersensitivity of rats.