生长抑素对溃疡性结肠炎大鼠细胞因子的影响

Effects of somatostatin on cytokines in rats with TNBS-induced ulcerative colitis

目的观察生长抑素(奥曲肽)对溃疡性结肠炎(ulcerative colitis,UC)大鼠肠黏膜组织中细胞因子的影响,探讨其对UC大鼠的保护作用及其机制。方法雌性SD大鼠随机分为正常对照组、奥曲肽对照组、模型组、治疗组,每组7只。模型组、治疗组大鼠用三硝基苯磺酸(TNBS)/乙醇溶液灌肠复制UC模型。观察各组实验大鼠体质量变化、大体及组织病理学改变。采用酶联免疫吸附法检测白细胞介素-6(IL-6)、白细胞介素-10(IL-10)、肿瘤坏死因子-α(TNF-α)的含量。结果奥曲肽可以缓解大鼠体质量的减轻,减少腹泻及便血的发生;并且能够显著改善结肠组织大体和组织学评分,降低IL-6、TNF-α的表达,同时使IL-10的表达增加。结论奥曲肽对TNBS诱导的大鼠UC具有显著保护作用,其作用机制可能与下调促炎细胞因子及上调抗炎细胞因子的产生和表达有关。

Objective To investigate the effects of somatostatin （octreotide） on the cytokine produced by colonic mucosa and to explore its possible mechanisms in the protection of TNBS - induced ulcerative colitis （ UC ） in rats. Methods 28 female SD rats were randomized into normal control group, octreotide control group, model group and treatment groups （n = 7）. UC in model group and treatment group was induced by intrareetal administration of TNBS （100 mg/kg in 50% ethanol）. Octreotide 50 ug/kg （ octreotide control group and treatment group） or saline 1 ml （ normal control group and model group） was administered intraperitoneally daily for 14 days. All animals were killed on day 15. The body weight loss of each rat, macroscopical and histological changes of the colon were observed. The levels of IL - 6, IL- 10 and tumor necrosis factor α （TNF-α） in colon supernatant were determined by. ELISA. Results Compared with model group, octreotide significantly inhibited the body weight loss and occurrence of diarrhea and rectal bleeding and obviously reduced colon mucosal IL - 6 and TNF - α expression level. The macroscopic score, microscopic score and the expression of IL - 10 were significantly improved in the octreotide treatment group. Conclusion Octreotide has no- ticeable protective effects on TNBS - induced ulcerative colitis in rats. The possible mechanism might＂ be related to the downregulation of the expression of proinflammatory cytokines and the upregulation of the expression of anti - inflammatory cytokines.