Shcherba V. Pathobiochemical peculiarities of gram-negative microflora effect on periodontal tissues in the chemical injury of liver

The thesis is devoted to the studying of biochemical, immune and morphological mechanisms of the periodontal tissues injury by gram-negative microflora endotoxin in animals with chronic toxic hepatitis and to the pathogenetic substantiation of nitric oxide synthase modulators using in such combined pathology. It has been shown that nitrooxidative stress plays important role in the pathogenesis of lipopolisaccharide periodontitis developing on a background of concomitant hepatitis. Activation of free radical oxidation processes, disorders of cytokine profile and humoral immune system, collagen catabolism activation, and the increase of glycoproteins and proteoglycans depolymerization reactions intensity are also important pathogenetic factors leading to the development of inflammatory changes and protein vascular-stromal dystrophy in periodontal tissues under conditions of gram-negative microflora endotoxin action on periodont of rats with concomitant chronic hepatitis. Nonselective NO synthase inhibitor N-nitro-L-arginine and highly selective iNOS inhibitor 1400W prevent the nitrooxidative stress in rats with combined pathology. 1400W and NO-synthase cofactor tetrahidrobiopteryn also partially prevent the development of oxidative stress, destructive processes in the connective tissue and improve the morphological structure of periodontal tissues, whereas N-nitro-L-arginine stimulates the processes of lipid peroxidation and has no effect on the morphological picture of the periodontal tissues of rats.