Mechanism of exacerbation of colonic damage in experimental colitis treated with celecoxib / 北京大学学报(医学版)

ABSTRACT

Objective:To assess the mechanism of exacerbation of colonic damage in rat colitis model induced by trinitrobenzene sulfonic acid(TNBS)treated wi th celecoxib(a selective COX-2 inhibitor).Methods:The rats w ere randomized in to four groups.Group 1 and Group 2 were study groups.Group 3 and Group 4 were control groups.Colitis was induced by intracolonic administration of TNBS(25 g /L)in a vehicle of 50% ethanol(0.25 mL)of study groups.The rats of study gro ups were treated orally,beginning 3 h before induction of colitis and continuin g twice per day thereafter for up to 7 d,with celecoxib(1.25 mg/kg,Group 1)a nd distilled water(1 mL/0.3 kg,Group 2)respectively.In control experiments,the rats of Group 4 were treated orally with celecoxib(1.25 mg/kg)twice per da y for up to 7 d.Group 3 rats were healthy control rats.All the rats that survi ved until the end of the experiment(d 7)were killed and the severity of coloni c inflammation was assessed.The COX-2 protein expression in colon tissues was e xamined by immunohistochemistry.Results:The colonic damage of Group 1 was exac erbated as compared with Group 2.The inflammatory index of colon tissues of Gro up 1(8.5?2.5)was significantly reduced,as compared with Group 2(13.5?1.9,P