Altered Colonic Motor Functions in Experimental Colitis of Guinea Pigs

Park, Hyojin; Ji, Sang Won; Lim, Jung Hyun; Lee, Sang In

Abstract

BACKGROUND/AIMS
Trinitrobenzene sulphonic acid (TNBS)-induced colonic inflammation in rat alters colonic motor function. The aims of this study were to investigate the effect of TNBS-induced colitis on the colonic motor function of a guinea pig along the course of colitis and to document persistently altered colonic motor function after resolution of inflammation.
METHODS
Colitis was induced in about 300 g male guinea pigs (Hartley) by intrarectal administration of 0.3 mL TNBS in 50% ethanol, while controls received 0.3 mL of 50% ethanol or not. After 24 hours, 48 hours, 72 hours, 1 week, and 2 weeks, the distal colon was taken for the investigation of gross and microscopic findings, muscle tension, and colonic transit.
RESULTS
Maximal mucosal injury and inflammation were evident from the 2nd day following the induction of colitis. Seven days after the induction of colitis, some portions of the damaged mucosa began to recover. Development of tension in response to carbachol was not altered significantly along the course of colitis. Colonic transit was delayed significantly at 3, 7, and 14 days after administration of TNBS.
CONCLUSIONS
Colonic transit in TNBS-induced colitis of guinea pigs is delayed, but not linearly related to the degree of inflammation. Delayed colonic transit is not related to the muscarinic receptor-mediated contractions of circular muscle from the inflamed colon. Further studies are required to determine the mechanism(s) involved in this motor change.