Indicators of Lipid Peroxidation Reactions and State of Structural Tissues of the Dentition System in Wistar Rats under Various Stress Regimes

Abstract

The aim of this research was to investigate the content of lipid peroxidation (LPO) products and components of antioxidant defense (AOD), as well as to evaluate morphometric parameters of the dentition system tissues in Wistar rats when modeling acute and chronic modes of immobilization stress. Methods and Results: The work was performed on young (2.5-3 months), sexually mature male rats of the Wistar line, weighing 200-220g. The design of the study consisted in evaluating biochemical and morphometric parameters at the stage before immobilization—intact animals (10 rats)— as well as in modeling various stress modes: acute stress (3 hours from the moment of 3-hour single immobilization) and chronic stress (1-hour immobilization with an interval of 72 hours between separate stress episodes on Days 1, 5, 9 and 13). Both modes included 20 rats. The intensity of lipid peroxidation-antioxidant defense processes was assessed using spectrophotometric and fluorometric methods. The microscopic and morphometric studies were performed in the light-optical microscope AxioScope A1 and included a detailed description of all changes in the tooth and periodontal tissues. We found that acute stress is accompanied by increased LPO reactions at the stage of primary and secondary products with simultaneous activation of antioxidant factors. In chronic stress exposure, there is an accumulation of thiobarbituric acid reactants, with a decrease in the level of non-enzymatic components—α-tocopherol, retinol, and oxidized glutathione. The changes in the state of the dentition system in Wistar rats was accompanied by an increase in the area of the microcirculatory bed of the periodontium and pulp and a natural reduction in the connective tissue area, with an increase in the thickness of vascular endothelium and an increased number of cellular elements that control metabolic processes, especially pronounced in acute stress. The change in the mode of stress exposure to chronic in animals of this line was characterized by generally similar changes with reduced reaction intensity. Conclusion: The processes of LPO-AOD and the indicators of the dentition system in Wistar rats undergo changes depending on the mode of stress exposure.

Keywords

• wistar rats
• lipid peroxidation
• periodontium
• pulp
• acute stress
• chronic stress