The dissertation is devoted to the research of Ca2+ - and Na+-ATP-dependent transport systems of peripheral blood lymphocytes of patients with rheumatic pathology. The significant reduction of ouabainsensitive Na+, K+-ATPase and Ca2+, Mg2+-ATP-ase activity of saponin-perforated peripheral blood lymphocytes has been shown. It is probably related to the energy insufficiency in patients with rheumatoid arthritis and ankylosing spondylitis. The comparative analysis of the kinetic properties of ouabainsensitive Na+, K+-ATPase and Ca2+, Mg2+-ATPase of peripheral blood lymphocytes of patients with rheumatoid arthritis and ankylosing spondylitis and practically healthy donors has been carried out. Analyzing the alterations in hydrolase activity of Na+, K+-ATPase it has been shown that in peripheral blood lymphocytes of patients with rheumatoid arthritis and ankylosing spondylitis the primary active transport of Na+ and K+ ions is slower and less intensive in comparison with practically healthy donors, but is characterized by almost the same capacity as in donors. Affinity constant of Na+, K+-ATPase for ATP in peripheral blood lymphocytes in patients with rheumatoid arthritis and ankylosing spondylitis is greater in 3.1 and 2.5 times respectively, in comparison with healthy donors. It has been found that the inhibition of Na+, K+-ATPase activity is not related to the reduction of maximum reaction rate, but is related to the decrease of Na+, K+-ATPase affinity to ATP in conditions of rheumatic pathology in immunocompetent cells. Mg2+-binding center of Na+, K+-ATPase and Ca2+, Mg2+-ATPase in patients with rheumatoid arthritis and ankylosing spondylitis remains native. It has been identified that affinity constant of Na+, K+-ATPase to Na+ ions in peripheral blood lymphocytes of patients with rheumatoid arthritis and ankylosing spondylitis is in 2.75 times lower than its value in healthy donors. Na+, K+-ATPase of peripheral blood lymphocytes of patients with rheumatoid arthritis retains its native receptor properties - sensitivity to ouabain does not change. Analyzing the alterations in hydrolase activity of Ca2+, Mg2+-ATPase it has been shown that affinity of Ca2+, Mg2+-ATPase of plasma membrane and membranes of endoplasmic reticulum for ATP does not significantly differ. It has been found that inhibition of examined enzyme systems occurs in mixed type and is related to the reduction of maximum reaction rate and to the decrease in Ca2+, Mg2+-ATPase affinity to ATP in conditions of rheumatic pathology in immunocompetent cells. It has been identified that Ca2+, Mg2+-ATPase has significantly lower affinity to Ca2+ in lymphocytes of persons with rheumatic disorders than in donors. It has been found that transport of Сa2+ ions by Ca2+, Mg2+-ATPase of lymphocyte plasmatic membrane in healthy donors is slower and less intensive, but is characterized by higher capacity in comparison with Ca2+, Mg2+-ATPase of endoplasmic reticulum. It has been shown that transport of Сa2+ ions through plasmatic membrane is characterized by lower capacity in peripheral blood lymphocytes of patients with rheumatoid arthritis and ankylosing spondylitis in comparison with practically healthy donors. The ultrastructural changes in peripheral blood lymphocytes of patients with rheumatoid arthritis after lymphocyte incubation with detergent saponin have been studied. It is noted that the addition of saponin leads to morphological transformation of lymphocytes, which are expressed mainly in the disintegration and disturbance of the plasma membrane integrity. It has been confirmed that such experimental approach to the studying of enzymatic spectrum of lymphocytes (including ATP-hydrolase systems), using perforated by saponin whole cell is perspective in biomedical research.
