PERMEABILITY OF THE BLOOD-BRAIN BARRIER IN TOXIC PARKINSONISM

Introduction. Parkinson's disease (PD) is a chronic neurodegenerative disease of the central nervous system with accumulation of alpha-synuclein and degeneration of nigrostriatal neurons. A number of studies have shown that one of the links in the pathogenesis of PD may also be microdamage of blood vessels. However, how these changes affect intercellular contacts of endothelial cells and the permeability of the blood-brain barrier has not yet been studied. The aim of the study. To study the permeability of the blood-brain barrier and the level of proteins of intercellular contacts in experimental toxic par-kinsonism. Material and methods. The study was performed on male Wistar rats weighing 280-320 g. Toxic parkinsonism was modeled by subcutaneous ad-ministration of rotenone at a dose of 2.5 mg/kg 1 time per day for 7 and 28 days. Dopamine levels were determined in the striatum and midbrain by the ELISA method, and the level of intercellular contact proteins occludin, E-cadherin and ZO-1 were analyzed in the cerebral cortex by the western blot. The permeability of the blood-brain barrier was assessed by penetration of Evans blue dye into brain tissue. Results. The administration of rotenone caused the development of experimental parkinsonism, which manifested itself in a typical clinical picture and a decrease in dopamine levels in the striatum and midbrain on days 7 and 28 of administration. At the same time, there was a decrease in the relative amounts of occludin, E-cadherin and ZO-1. These biochemical changes led to the permeability of the blood-brain barrier to the Evans blue dye on the 7th and 28th days of the experiment, which indicates an increase in the permeability of the blood-brain barrier. Conclusion. Thus, in rotenone-induced parkinsonism, the permeability of the blood-brain barrier increases, which is caused by a decrease in specific tight junction proteins that form the connection between endothelial cells and the perivascular microenvironment. The results obtained make a signifi-cant contribution to modern understanding of the pathogenesis of Parkinson's disease and allow to identify new approaches to its treatment.