外源性硫化氢对三硝基苯磺酸诱导的大鼠肠壁纤维化的影响

目的 探讨外源性硫化氢对三硝基苯磺酸(trinitrobenzene-sulfonic acid, TNBS)诱导的大鼠慢性结肠炎肠壁纤维化的影响。方法 健康雌性SD大鼠60只,随机分为乙醇对照组、模型组、低剂量硫氢化钠(NaHS)组、高剂量NaHS组(15只/组),后三组建立TNBS诱导的慢性结肠炎肠壁纤维化模型。实验第3周开始,低剂量NaHS组、高剂量NaHS组分别给予腹腔注射H2S供体NaHS[14.4μmol/(kg·d)或36.0μmol/(kg·d)],对照组和模型组予同等体积的生理盐水腹腔注射,实验期间观察各组大鼠每日的一般情况,第35天处死全部大鼠,采用去蛋白法测血清中的H2S含量,分离结肠行大体形态学评分、组织学评分、计算胶原面积百分比,RT-PCR法测定胱硫醚-β-合酶(CBS)mRNA,ELISA法测COLIα2、COLⅢ、TGF-β1、TNF-α。结果 NaHS组H2S含量、CBSmRNA高于模型组,高剂量NaHS组高于低剂量NaHS组；NaHS组大体形态学评分、组织学评分、胶原面积百分比、COLIα2、COLⅢ、TGF-β1、TNF-α低于模型组,高剂量NaHS组低于低剂量NaHS组,差异均有统计学意义(P<0.05)。结论 在TNBS诱导的大鼠慢性结肠炎肠壁纤维化模型中,外源性硫化氢可以使结肠组织CBSmRNA表达增加,同时具有抗炎、抑制肠壁纤维化的作用,且与剂量呈正相关。
Objective To investigate the effect of exogenous hydrogen sulphide on chronic colitis and intestinal fibrosis induced by trinitrobenzene-sulfonic acid(TNBS)in rats. Methods Sixty healthy femal Sprague-Dawley rats were randomly divided into 4 groups: alcohol-control group, model group, low-dose NaHS and hige-dose NaHS group. Intestinal fibrosis were induced by TNBS in model group, low-dose and hige-dose NaHS groups. At the beginning of the third week, rats in NaHS groups were injected intraperitoneally once a day with NaHS(14.4μmol/kg and 36.0μmol/kg,respectively)starting from the 3rd week, an equal volume of normal saline was injected in the alcohol-control and model groups. All rats were sacrificed at the end of the 5th week. Serum H2S level was measured； colons samples were collected for pathological examination and measurement of collagen area, the expression of CBS mRNA was determined by RT-PCR, COLIα2, COLⅢ, TGF-β1, TNF-α were detected by ELISA. Results The macroscopic and microscopic scores, collagen area, the level of COLIα2、 COLⅢ、TGF-β1、TNF-α were higher in model group than in NaHS groups, while these in high-dose NaHS group were significantly lower than in low-dose NaHS group(P<0.05). The level of serum H2S and CBS mRNA were significantly higher in NaHS groups than those in model group(P<0.05), and these parameters were higher in hige-dose NaHS group than those in low-dose NaHS group(P<0.05). Conclusion Results indicate that exogenous hydrogen sulphide has anti-inflammatory and anti-fibrotic effects in a dose-dependent manner in rats with chronic colitis and intestinal fibrosis induced by TNBS