Effect of lipopolysaccharide on the development of oxidative-nitrosative stress in salivary glands and soft periodontal tissues of rats under conditions of water avoidance stress

Introduction and aim. Violation in the salivary glands will inevitably cause changes in periodontium, and periodontitis can disrupt the functioning of the salivary glands. The purpose of the work is to evaluate changes in NO-synthase and arginase activities, pro- and antioxidant balance in rat salivary glands and soft periodontal tissues during administration of bacterial lipopolysaccharide (LPS) and water avoidance stress (WAS) modeling. Material and methods. The experiment was performed on 24 rats. The animals were divided into 4 groups: control, WAS, animals injected intraperitoneally with 0.4 μg/kg of bacterial LPS of Salmonella typhi, WAS+LPS. Results. Water avoidance stress led to decrease of inducible NO-synthase (iNOS) activity in salivary glands by 1.63 times, but decreased arginase activity by 1.15 times, superoxide production increased by 1.53 times, catalase activity decreased by 1.2 times, and malonic dialdehyde (MDA) increased by 1.19 times compared to the control. Lipopolysaccharide led to increase of constitutive NO-synthases (cNOS) activity in salivary glands by 1.48 times, but decreased arginase activity by 6.15 times, catalase activity increased by 2.6 times and superoxide dismutase activity decreased by 2.74 times, and MDA increased by 6.84 times compared to the control. Water avoidance stress + LPS in salivary glands led to decrease of cNOS and arginase activity by 1.09 and 1.19 times, respectively, superoxide production increased by 1.88 times, catalase and superoxide dismutase activity decreased by 1.06 times and 1.34 times, respectively, and MDA increased by 2.44 times compared to the control. Water avoidance stress led to increase of iNOS activity in periodontium by 1.44 times and arginase activity decreased by 1.37 times, superoxide production increased 1.32 times, catalase activity and superoxide dismutase activities decreased by 1.27 times and by 1.53 times, respectively, and MDA increased by 1.31 times compared to the control. Lipopolysaccharide led to increase of iNOS activity in the periodontium by 3.88 times, arginase activity decreased by 2.69 times, superoxide production increased 1.64 times, catalase activity increased by 4.32 times, and MDA increased by 4.51 times compared to the control. Water avoidance stress + LPS in periodontium led to increase of iNOS and cNOS activities by 1.95 times and 1.53, respectively, arginase activity decreased by 1.39 times, superoxide production increased 1.66 times, catalase activity increased by 1.11 times, and MDA increased by 1.53 times compared to the control. Conclusion. The combination of LPS and WAS leads to changes in NO production and oxidative stress in salivary glands and the periodontium.