RESUMO
Aim: To evaluate the effect of restraint stress on the reactivation of ulcerative colitis in rats that have been chemically-induced with ulcerative colitis after allowing progression of natural healing to take place. Study Design: 36 animals were used for this study, and were divided into three groups; control (group 1), colitis alone (group 2) and colitis + restraint stress (group 3). Methodology: 36 healthy female wistar rats of weight of 170±20 were used. Colitis was induced by intra-rectal administration of 1 mL/100 g body weight of 7% acetic acid. Fourteen days post colitis induction, colitis + restraint stress group animals were exposed to restraint stress for six consecutive days while animals in colitis alone group were not. Colon levels of Malondialdehyde (MDA), Glutathione (GSH) concentration, Superoxide dismutase (SOD), Catalase (CAT) and Myeloperoxidase (MPO) activities were measured spectrophometrically. Histological assessment was also done on the colon tissues. Place and Duration of Study: Department of Physiology, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria, between April 2019 and August 2019. Results: Colitis caused significant increase in the levels of GSH, SOD, CAT and MPO on the 3rd day. On the 14th day, group 2 showed lowered level of antioxidant activities (SOD and CAT) when compared with the 3rd day, while on the 20th day, group 3 animals exhibited increased levels of antioxidant activities (as well as increase in MDA and MPO) when compared to group 2 and group 1. Histological examination revealed cyst in the mucosal layer, infiltration of inflammatory cells anddilation of vessels in the colitis + restraint stress on the 20th day post colitis induction. Results are considered significant when p≤0.05. Conclusion: The results of this study showed that restraint stress is capable of reactivating and inhibiting colitis healing in acetic acid-induced ulcerative colitis rats