PROTECTIVE EFFECT OF N(NITRO-L-ARGININE IN THE RAT MODEL OF ACETIC ACID INDUCED COL1TIS

Abstract

Recently, in inflammatory bowel disease (IBD), increased nitric oxide (NO) production and NO synthase activity have been reported. Inhibitors of NO such as NG nitro-L-arginine methyl ester have treated the mucosal injury in the rat model of trinitrobenzene sulphonic acid or acetic acid induced colitis. In this study, effect of N(nitro-L-arginine (N(NA), another inhibitor of NO, in the rat model of acetic acid induced colitis was investigated. Sprague-Dawley rats were divided into three groups: Group 1 (sham-operated, n: 6), Group 2 (control, n: 6) and Group 3 (treated with N(NA, n: 6). The rats in sham group received only 0.9 % NaCl, 2 ml transanally and 3 ml intraperitoneally after anesthesia. In order to induce experimental colitis, 2 ml of 5 % acetic acid was introduced by the way of anus in the rats in other groups. Then, 3 ml of 0.9 % NaCl was given intraperitoneally to the rats in control group. The rats in Group 3 received N(NA (300mg/kg) intraperitoneally. Sections of colon for morphological studies and malondialdehyde (MDA) values were obtained after 24 hours. Statistical analysis for morphological differences was performed according to Fisher's exact test, and for MDA values according to Kruskall-Wallis and Mann-Whitney U tests. Mucosal injury was less in Group 3 than in Group 2 (p<0.05). Severe mucosal injury was observed in Group 2 while no mucosal injury in Group 1. No significant differences were seen among the groups for MDA values. In this study, we saw that experimental colitis may be induced by 5 % acetic acid, and concluded that N(NA has treated experimental colitis.