目的 了解SERT表达调控在PI-IBS的发病机制. 方法 60只雄性成年SD大鼠随机分为4组,每组15只.M组用无菌生理盐水灌胃,2 ml/d/只;A、B、C组分别用ATCC 2151菌种灌胃,浓度分别为108、109、1010 cfu/ml,2ml/d/只.4组均持续灌胃7d;感染后第3、7、14、28、42、56、70 d检测肠道感染状态,第70 d检测腹壁撤退反射(AWR)评分、肠道传输时间、粪便Bristol评分及结肠粘膜SERT mRNA和蛋白表达情况. 结果 急性感染期大鼠感染个体数随菌液浓度增加而增多;感染恢复期C组粪便湿重比明显增加;感染后第70 d,各组大鼠均脱离感染状态;B、C组大鼠AWR评分显著增加(P＜0.05),肠道传输时间缩短(P＜0.05),以C组尤甚,结肠SERT mRNA及蛋白表达量C组下调更显著. 结论 高浓度ATCC 2151菌液持续灌胃可增加造模成功率,引起大鼠内脏敏感性增强肠道动力紊乱,结肠粘膜SERT表达下调.“,”Objectives Serotonin transporter (SERT) can absorb serotonin and may play a key role in irritable bowel syndrome (IBS).The expression of SERT is crucial to the development of IBS and is useful in personalized treatment.The aim of the current study was to create a rat model of post-infectious IBS (PI-IBS) through a decrease in SERT and to facilitate future study of PI-IBS.Methods Sixty adult male SD rats were randomly assigned to one of four groups (n=15 per group):M,A,B,C.Rats were allowed to acclimate for 7 d before treatment.Before inoculation with C.jejuni,all rats were gavaged with 1 ml of 5％ sodium bicarbonate solution to neutralize stomach pH.About 30 min later,the M group were gavaged with 2 ml of sterile saline for 7 d.Group A was gavaged with 108 cfu/ml of C.jejuni (ATCC 2151)for 7 d,group B was gavaged with 109 cfu/ml,and group C was gavaged with 1010 cfu/ml.Biochemical tests and DNA agarose gel electrophoresis were used to assess colonization by C.jejuni.An intestinal infection was detected 3,7,14,28,42,56,and 70 d after infection,and the abdominal withdrawal reflex (AWR) score,the colon transit test,the Bristol stool grade,and levels of SERT mRNA and protein expression were used to evaluate IBS after 70 d.Results During acute infection,bouts of acute infection increased as the concentration of bacteria increased.In the convalescent phase,elimination of water increased significantly in group C.The relative water content of stool was greater in group C after 3 d (P=0.012 for group M,P=0.010 for group A,P=0.027 for group B) and after 7 d (P=0.024 for group M,P=0.031 for group A,P=0.025 for group B).After 42 d,95％ of the rats were no longer infected with C.jejuni.After 56 and 70 d,none of the rats tested positive for C.jejuni.After 70 d,tests were done to evaluate PI-IBS.The AWR score was significantly higher and the colon transit time was briefer for groups B and C (P＜0.05),and especially for group C (vs.M P=0.016;vs.A P=0.042).Moreover,the level of SERT mRNA expression decreased significantly in group C (0.75,0.74,and 0.83 times the level of expression in groups M,A,and B),as did the level of protein expression (0.51,0.80,and 0.76 times the level of expression in groups M,A,and B).Conclusion A high concentration of ATCC 2151 increased the success rate of the model,causing visceral hypersensitivity,disruption of intestin'al motility,and a decrease in SERT expression.