Disorders of the Biochemical Composition of the Periodontium in Rats with Periodontitis and Chronic Pain Syndrome.

We analyzed the composition of the periodontal tissue in rats with experimental periodontitis and chronic pain syndrome. Chronic pain syndrome was induced by bilateral ligation of the sciatic nerve; experimental periodontitis was modeled by application of eight-shaped silk thread ligature to lower jaw incisors followed by its immersion into the periodontal groove and fixation with additional knots. A decrease in the concentration of oxyproline, glycosaminoglycans, and catalase activity and an increase in the content of malondialdehyde and acylhydroperoxides in the periodontal tissue were found in animals with experimental periodontitis throughout the experiment (7-21 days). In animals with chronic pain syndrome, modelling of experimental periodontitis led to more pronounced decrease in the concentration of oxyproline and glycosaminoglycans, increase in the content of acylhydroperoxides and malondialdehyde, as well as a decrease in catalase activity in the periodontal tissue.