高空悬跳致应激性溃疡大鼠模型的建立及不同预处理的干预效果

Establishment of a rat model of stress-induced gastric ulcer by suspending at a great height and intervention effects of different pretreatments

目的建立高空悬跳致应激性溃疡(stress ulcer,SU)大鼠模型,并探讨不同预处理对溃疡大鼠的影响及机制。方法①48只SD大鼠进行高空悬跳建模实验,按随机数字表法分为6组(n=8):高空悬跳组大鼠分别从17 m高空悬跳30 min(H17-30组)、40 min(H17-40组)、50 min(H17-50组),34 m高空悬跳40 min(H34-40组)和46 m高空悬跳40 min(H46-40组),以经典束缚浸水应激法建SU模型的束缚浸水组(RWIS组)作为对照。观察各组大鼠胃黏膜溃疡的发生率,Guth法评价溃疡指数,对溃疡局部胃组织进行病理学检查。②40只SD大鼠进行预处理干预实验,按随机数字表法分为5组(n=8):正常对照组(C组)、模型组(H17-40组)、雷尼替丁组(R组)、参苓白术散组(S组)和低空悬跳预适应组(P组)。Guth法评价各组大鼠溃疡指数,测定胃酸pH值、血清SOD活性和MDA含量。结果①大鼠自17 m高空分别悬跳30、40、50 min,均可发生胃溃疡,与RWIS组比较,溃疡指数差异均无统计学意义,并随时间的增加,溃疡指数逐渐升高。大鼠分别从17、34、46 m高空悬跳40 min,均可发生胃溃疡;与RWIS组比较,H34-40组、H46-40组溃疡指数显著升高(P<0.05),H17-40组溃疡指数与束缚浸水组最为接近,差异无统计学意义。②与H17-40组比较,R组、S组和P组溃疡指数均显著降低(P<0.05),pH值显著增高(P<0.05),SOD活性显著增高(P<0.05),MDA含量显著降低(P<0.05),预处理3组间两两相比,溃疡指数、pH值、SOD活性、MDA含量差异均无统计学意义。结论高空悬跳刺激可成功建立应激性溃疡大鼠模型,并且溃疡程度与悬跳持续时间和高度有关;雷尼替丁、参苓白术散、低空悬跳预处理均可通过降低胃酸和减少氧自由基有效预防或减轻溃疡程度。

Objective To establish a rat model of stress-induced gastric ulcer by exposure to hanging at a great height and assess the intervention effects of different pretreatments in this model.Methods Fortyeight SD rats were randomly divided into 6 groups,including a restraint water-immersion stress(RWIS)group and 5 height exposure groups where the rats were exposed to different heights(by suspending the rats with rubber bands tied to their hind limbs to simulate bungee jump)at 17 m for 30 min(H17-30 group),40 min(H17-40 group),or 50 min(H17-50 group),at 34 m for 40 min(H34-40 group),or at 46 m for 40 min(H46-40 group).The rats were examined for occurrence of gastric ulcer,ulcer index and gastric mucosal pathology after the exposures.Another 40 SD rats were randomized into normal control group,model group(H17-40 group),ranitidine group(group R),Shenling Baizhu San group(group S)and preconditioning group(group P)with corresponding pretreatments before height exposure at 17 m for 40 min.The incidence of gastric ulcer,gastric acid pH value,serum SOD activity and MDA content of the rats were then examined.Results Height exposures at 17 m for 30,40,and 50 min all induced gastric ulcer in the rats,whose ulcer indexes was similar with that in RWIS group but appeared to increase with the exposure time.Exposures to heights of 34 m and 46 m for 40 min also induced gastric ulcer in the rats and resulted in significantly higher ulcer indexes than that in RWIS group.Compared with those in group H17-40,the ulcer incidence and MDA content were significantly reduced while the pH value of the gastric acid and serum SOD activity were significantly increased in group R,group S and group P(all P<0.05);there was no significant difference in the ulcer index,gastric acid pH value,SOD activity or MDA content among the latter 3 groups.Conclusion Rat models of stress-induced gastric ulcer can be established by height exposure,and the severity of gastric ulcer is correlated with the height and duration of the exposure.Pretreatment with ranitidine,Shenling Baizhu San and preconditioning by hanging at a low height can effectively prevent or reduce the severity of stress-induced gastric by reducing gastric acid and oxygen free radicals.