The nitric oxide(NO) is a free radical synthesized from some cells of our organism. It presentswith an ample specter of physiological actions being the most important itsmechanism of action in the relaxation of the smooth musculature, its neurotransmissoractivity in some systems and its involvement in the inflammatory process. TheNO is synthesized in different tissues by the conversion of the L-arginine inL-citruline with the action of the enzyme nitric oxide sintase(NOS).
OBJECTIVES: the aim of this study is to demonstrate the involvement ofnitric oxide in the inflammatory intestinal process of Wistar rats submittedto experimental colitis with ascetic acid.
MATERIAL AND METHODS: 20 male Wistar rats had been used with weight between250 and 350 g divided in two groups of 10 animals. The animals of the groupin study had been submitted to intracolonic administration, by enema, of a solutionwith acid ascetic diluted to 7% - 3 ml. The control group received only enemawith saline solution. The histological scores, the expression of the enzymenitric oxide sintase (iNOS) and the sphincteric anal pressure had been evaluated.
RESULTS: The histological scores had presented a significant rise inthe group colitis when compared with the control group in the macroscopic aswell as in the microscopical evaluation. The expression of the enzyme iNOS wasalso significantly higher in the colitis group when compared to the controlgroup. The sphincteric anal pressure was significantly lower in the group colitiswhen compared to control group.
CONCLUSION: The animals submitted to the experimental colitis presentedan increase of the iNOS expression. This increase, associated with the consequentincrease in nitric oxide level, causes a reduction of the sphincteric anal pressurelevels.
