[Content and metabilism of nitric oxide in substrates of oral cavity and their role in pathogenesis of periodontite disease].

Content and metabolism of free NO in saliva, fluids of periodontal pockets and gingival tissue has been investigated by EPR (electron paramagnetic resonance) method with the use of nitric oxide spin-trap in patients suffering from periodontitis. It was found that increased generation of nitric oxide at early stages of periodontitis is of protective nature. However, at serious disorders of mitochondrial respiration and exaggerated formation of generators of reactive oxygen, nitric oxide converts into citotoxic peroxinitrite leading to destruction of parodontal tissue; part of free nitric oxide produces FeSNO, which in turn, supports and decreases content of free NO in gingival tissue. As a result, decreases local antimicrobial protection, hemocirculation, tissue nutrition, progresses inflammation. Periodontitis decreases local immunity due to NO deficiency in gingival tissue. Reduced content of NO in gingival tissue decreases regeneration ability of cells, which in turn, leads to deterioration on gingival tissue.