目的 建立感染后肠易激综合征(PI-IBS)肝郁脾虚夹湿证病证结合大鼠模型并对模型进行评价.方法 将200只Wistar大鼠按体质量随机区组分为正常组、感染组、感染+应激组、感染+应激+外湿组、醋酸+应激组,每组40只,共8周.采用旋毛虫感染、慢性束缚应激、人工高湿环境及醋酸灌肠分别对各组大鼠进行相应干预.分别于第1、2、4、6、8周,检测各组大鼠体质量增长率、24 h进食量与饮水量、粪便含水率,采用旷场实验、糖水消耗实验检测各组大鼠的行为特点,采用腹壁撤退反射(AWR)实验检测各组大鼠的内脏敏感性,HE染色法观察各组大鼠结肠组织的炎症程度,酶联免疫吸附测定(ELISA)法检测各组大鼠结肠组织5-羟色胺(5-HT)及水通道蛋白4(AQP4)含量.结果 造模第1~8周,感染+应激+外湿组和醋酸+应激组大鼠体质量增长率均较正常组降低,感染+应激+外湿组和感染+应激组大鼠在造模第2~8周末24 h进食量均低于正常组,造模第2周末感染+应激+外湿组、醋酸+应激组和感染+应激组大鼠24 h饮水量较正常组降低;感染+应激+外湿组大鼠粪便含水率在造模第1、6、8周末均高于正常组(均P<0.05).造模第4周末感染+应激+外湿组和醋酸+应激组大鼠活动总距离均低于正常组;感染+应激+外湿组大鼠在造模第1、4、8周末糖水偏好率均较正常组下降,且在第4、8周末较醋酸+应激组也降低(均P<0.05).感染+应激+外湿组大鼠在第1周末60和80 mmHg(1 mmHg ≈ 0.133 kPa)压力下、第4周末40、60、80 mmHg压力下和第6、8周末20、40、80 mmHg压力下AWR评分均高于正常组(均P<0.05).造模第2、4周末各干预组大鼠结肠黏膜均可见大量炎症细胞浸润,炎症程度评分均高于正常组(P<0.05),第6、8周末各干预组肠黏膜组织炎症细胞浸润不明显,结肠黏膜恢复正常.造模的第6、8周末,感染+应激组、感染+应激+外湿组及醋酸+应激组大鼠结肠组织5-HT含量均高于正常组(P<0.05);造模第4周末,感染+应激+外湿组及醋酸+应激组大鼠结肠组织AQP4含量较正常组降低,第6周末,除醋酸+应激组外,其余各组AQP4含量均低于正常组,且感染+应激+外湿组低于醋酸+应激组(P<0.05);第8周末,仅感染+应激+外湿组AQP4含量低于正常组(P<0.05).结论 采用旋毛虫感染、慢性束缚应激及人工高湿气候复合因素能够制备出较稳定的PI-IBS肝郁脾虚夹湿证病证结合大鼠模型.
Objective We aimed to establish and evaluate a rat model of post-infectious irritable bowel syndrome(PI-IBS)with the pattern of liver depression and spleen deficiency coupled with dampness.Methods First,200 rats were randomly divided into the normal group,the infection group,the infection+stress group,the infection+stress+external dampness group,and the acetic acid+stress group(n=40 rats per group)for eight weeks.The rats were treated with Trichinella spiralis infection,chronic restraint stress,an artificial high-humidity climate,and/or acetic acid enema.Weight growth rate,24-hour food intake and water intake,and the fecal moisture percentage were recorded.The open field test and the sucrose consumption test were used to determine the behavioral characteristics of rats in each group.The abdominal withdrawal reflex(AWR)test was used to determine visceral sensitivity.The contents of 5-hydroxytryptamine(5-HT)and aquaporin 4(AQP4)in colon tissue were detected by ELISA.Results Compared with the normal group,the weight growth rate of rats in the infection+stress+external dampness group and the acetic acid+stress group was lower from Week 1 to Week 8 of modeling.The 24-hour food intake of rats in the infection+stress+external dampness group and the infection+stress group was lower than that in the normal group from Week 2 to Week 8 of modeling.At the end of week 2 of modeling,the 24-hour water intake of rats in the infection+stress+external dampness group,the acetic acid+stress group,and the infection+stress group was lower than that in the normal group.The fecal moisture percentage of rats in the infection+stress+external dampness group was higher than that in the normal group at the end of Week 1,6,and 8(P<0.05).At the end of Week 4 of modeling,the total distance in the open field test in the infection+stress+external dampness group and the acetic acid+stress group was shorter than that in the normal group.The sugar preference rate in the infection+stress+external dampness group was lower than that in the normal group at the end of 1,4,and 8 weeks and lower than that in the acetic acid+stress group at the end of Week 4 and 8(P<0.05).The AWR scores of rats in the infection+stress+external dampness group were higher than those in the normal group after week 1 at 60 and 80 mmHg(1 mmHg≈0.133 kPa),after Week 4 at 40,60,and 80 mmHg,and after Week 6 and 8 at 20,40,and 80 mmHg(P<0.05).At the end of Week 2 and 4,a large number of inflammatory cells were infiltrated in the colonic mucosa of the intervention groups,and the inflammation score was higher than that of the normal group(P<0.05).At the end of weeks 6 and 8,the inflammatory cell infiltration in the intestinal mucosa of the intervention groups was not obvious,and the colonic mucosa returned to normal.At the end of weeks 6 and 8,the 5-HT content was higher in the infection+stress group,the infection+stress+external dampness group,and the acetic acid+stress group than in the normal group(P<0.05).After Week 4,the AQP4 content was lower in the infection+stress+external dampness group and the acetic acid+stress group than that in the normal group(P<0.05).After week 6,compared to the normal group,the AQP4 content was lower in all groups except for the acetic acid+stress group,and the AQP4 content in the infection+stress+external dampness group was lower than that in the acetic acid+stress group.After week 8,only in the infection+stress+external dampness group the AQP4 content was lower than in the normal group(P<0.05).Conclusion The combination of Trichinella spiralis infection,chronic restraint stress,and an artificial high-humidity climate can be used to prepare a relatively stable and reliable rat model of PI-IBS with the pattern of liver depression and spleen deficiency with dampness.