Variation Of COX-2 And INOS Expression In Periodontal Tissues Of Adult Patients With Periodontitis

Objective:The cyclooxygenase (COX) is oenzymes, known as prostaglandin(PG) rate--limiting synthase, catalyze the metabolism of arachidonic acid to PGs. COX-2, an inducible enzyme, is associated with inflammatory diseases and carcinogenesis. Nitric oxide (NO) is an important signaling molecule that regulates osteoclasts function. NOS was known as NO synthesis key synthase.NOS exists in three distinct isoforms:neuronal NOS(nNOS), endothelial NOS (eNOS), and inducible NOS(iNOS). While eNOS and nNOS release small amounts of NO for a short period of time following receptor stimulation, iNOS is expressed in response to proinflammatory stimuli and produces large amount of NO. To study the changes of COX-2 and iNOS expression in inflamed gingival of adult patients with periodontitis.Methods:15 adult patients with periodotitis(A P),15 patients with gingivitis(G) and 14 health control(H) were selected. Gingival tissues were surgically excised during Operations.COX-2 and iNOS immunohistechemistry staining were done to compare expression variations.Results:The expression of COX-2 was hardly positive in normal group. The expression of COX-2 was positive in the periodontitis group and gingivitis group.There were not significant differences between the gingivitis group and normal group (P>0.05). There were significant differences between the periodotitis group and normal group (P<0.05). There were not significant differences between the periodotitis group and gingivitis group (P>0.05).â‘¡The expression of iNOS was hardly positive in normal group. The expression of iNOS was stronger positive in the periodontitis group and gingivitis group. There were significant differences between the gingivitis group and normal group (P<0.05). There were significant differences between the periodontitis group and normal group (P<0.05). There were not significant differences between the periodotitis group and gingivitis group (P>0.05).â‘¢With the developing of inflammation, The positive expression of iNOS was stronger than the expression of COX-2.There were significant differences between the periodontitis group and gingivitis group in the positive expression of COX-2 and the positive expression of iNOS. (P<0.05)Conclusion:Periodontitis will increase the expression of COX-2 and iNOS in adult patient with periodontitis, COX-2 and iNOS may play an important role in the destruction of periodontium and resorption of alveolar bone.