Age Dynamics of Content of Hydrogen Sulphide, Nitric Oxide Metabolites, Indicators of L-Arginine/Arginase System in the Oral Fluid

Aim. To examine age dynamics of content of hydrogen sulphide, nitric oxide metabolites, and indicators of L-arginine/arginase system in the oral fluid of practically healthy individuals of different age groups. Methods: The study involved 103 patients divided into five age groups (18-89 years). The content of hydrogen sulphide, the sum of nitrites and nitrates, peroxynitrite concentration, L-arginine content and arginase activity were determined in the oral fluid. Statistical analysis was performed using Student’s t-test. Results: With age (especially after 45 years), the content of nitric oxide metabolites in the oral fluid increases, toxic peroxynitrite accumulates. These changes are observed against the background of relative inertia of L-arginine/arginase system and a decrease the concentration of hydrogen sulphide in the advanced and senile people. The changes in the nitric oxide system may adversely affect the functioning of the system for regulation the vascular tone and immune response, the potential vulnerability of the tooth-jaw system to various diseases. The identified features may be associated with the development of nitroso-oxidative stress, which increases the risk of inflammatory processes occurrence in oral tissues, such as gingivitis and periodontitis, and may also characterise a change of the balance between the pathogenic and beneficial bacteria in the oral cavity that progresses with age. Conclusions: The detected changes in the nitric oxide system and features of hydrogen sulphide synthesis may be important for understanding the age-related processes of aging in the organism and for developing the new approaches for prevention and treatment of dental diseases.