NO Expression In The Development And Progression Of Periodontal Disease

Objective:To make a clear expression of NO’s occurrence and explore the mechanisms in the development and progression of periodontal disease.Methods:1.Build experimental rat model of periodontitis SD: Take 36 healthy male SD rats, approximately aged 15 weeks, whose weight is 201.79 ± 17.86 g, complete dentition, normal occlusion, no caries and no periodontal tissue disease. Then divided randomly the rats into normal control group(9), two weeks group(9), four weeks group(9) and six weeks group(9). Periodontal surgery using simple ligation rats with bilateral ligation of the maxillary first molar.Before and after surgery rats were fed with conventional feed and water. Respectively after 2w, 4w, 6w when rats were observed ligature mouth existence, and periodontal tissue changes.2.Using classic hematoxylin- eosin to stain the rats’ periodontal tissue sections and observe the pathological changes by light microscopy.3.Using immunohistochemistry to stain the rats’ periodontal tissue sections and observe i NOS2 how to express in periodontal tissues by light microscopy.4.Determination of NO levels of Serum in each group of rats with nitrate reduction. Results:1.The results of weight changed: after a week, the rats’ weight lost in different degrees and food intake decreased. Two weeks after surgery weight of rats began to recover, and the weight show a gradual increasing trend over time, Due to loose teeth 6w rats’ food intake decreased and weight loss occurred, but compared with the control group, no significant difference. Thus during the experiment, the rat periodontitis had no significant effect on the body weight over time.2.The issue successfully established animal model of periodontitis in SD rats: before and after periodontal four groups remains environment unchanged,and the mice were fed with conventional feed and water. After surgery respectively in 2w,4w,6w to make clinical observations about periodontal situation. Postoperative 2w,gingival swelling, mild hyperemia, a small amount of bleeding on probing; postoperative 4w, gums, turned red, soft texture and rounded edges, with 0.5mm periodontal pocket, bleeding easily on probing; 6w later, the gums turned dull-red, soft texture, partial erosion, explore and 0.7mm pockets, bleeding easily on probing. HE staining showed perivascular connective tissue and collagen damage, and visible osteoclasts and resorption. Clinical and pathological examination showed successfully established animal model of periodontitis.3.i NOS2 in SD rats’ Periodontal tissue:Using immunohistochemistry gray values to represent i NOS2 periodontal tissue expression. Normal control group, 2w group, 4w group, 6w group of gray values were 202.31 ± 3.16, 194.46 ± 1.91, 189.69 ± 1.89, 184.65 ± 1.65. ANOVA showed that F = 101.824, p <0.05, which shaved significant difference exist and with significant statistical.4.NO’s expression in the serum of SD rats: normal control group, 2w group, 4w group, 6w NO levels of serum were 14.32 ± 3.43μmol / L, 26.11 ± 2.32μmol / L, 35.38 ± 1.66μmol / L, 47.65 ± 6.81μmol / L. ANOVA showed that F = 108.255, p <0.05, which meant significant difference existed and was significant statistically. Conclusion:1.The development of periodontitis had no significant effect on SD rats’ body weight and food, although compared with the control group, rats 6w group appeared normal weight dropped during the sixth week, which meant no significant difference. So the periodontitis and changes in body weight of rats is not relevant.2.With the progress of the periodontitis, SD rats immunized group of gray values arein descending order, and NO levels are in ascending order. With the progress of the periodontitis, NO levels of rat periodontal tissue and serum increased.