Біохімічні зміни пародонта в щурів на тлі дії тютюнового диму
Authors: Lavrin O. Ya. , Shcherba V. V. , Krynytska I. Ya. 
Published: May 2017

Introduction. In our days, smoking is one of the most important risk factors for inflammatory diseases. There is a lot of scientific data, devoted to research the effects of smoking on periodontal status. However, some aspects such as the status of free-radical oxidation, is left without proper attention.The aim of the study – to investigate experimentally the indices of free radical oxidation in periodontal tissues on the background of smoking.Methods of the research. Experimental studies were performed on 20 adult male albino rats weighing 160-180 g. Animals were divided into 2 groups: control (10 animals) and experimental (10 animals). Modeling of passive smoking was carried out by placing rats in a specially designed chamber in which tobacco smoke was distributed. The duration of the experiment was 21 days. The concentration of 8-isoprostane was determined by ELISA method using a set of "8-isoprostane ELISA» company «USBiological» (USA). Quantitative assessment of the content of metabolites of nitrogen (II) oxide was carried out by determining their amount. The content of reduced glutathione, superoxide dismutase and catalase activity in periodontal tissue homogenate were determined by conventional methods.Results and Discussion. Concentration of 8-isoprostane in supernatant of periodontal homogenate in rats of control group was (3.94±0.18) pg/ml. In experimental animals this index was significantly increased in 2.9 times. This indicates that despite the action of tobacco smoke in periodontal tissues oxidative stress develops, characterized by the increasing intensity of the production of reactive oxygen species. On 22 day of the experiment, we have observed a significant decrease in superoxide dismutase activity in periodontal tissue homogenate by 40.9 % and catalase activity in 2.4 times compared to the control group. It is known that SH-groups (such as cysteine and methionine fragments of protein molecules) are most easily oxidized by reactive oxygen species to form a reversible and irreversible modifications. On 22 day of the experiment, we have observed a significant decrease in glutathione content in periodontal tissue homogenate by 24.4 % compared to the control group. The content of NO metabolites in supernatant of periodontal homogenate in rats of experimental group was significantly decreased in 2.1 times. The powerful factors that inactivate NO, are free radicals, among them – superoxide radical. Its interaction with NO leads to formation of peroxynitrite that as a strong oxidant has high degree of cytotoxicity.Conclusions. In rats on the background of tobacco smoke in periodontal tissues significantly increases the generation of reactive oxygen species, reduces superoxide dismutase, and catalase activity and glutathione content, indicating a marked imbalance of free radical homeostasis. On the background of tobacco smoke in periodontal tissues occurs inhibition of nitroxydergic processes through significant reduction of nitric oxide metabolites content, which reduces the protective antibacterial potential.