RESUMEN
The comparative analysis of the kinetic properties of ouabain-sensitive Na+, K+ -ATPase activity of saponin-perforated blood lymphocytes of donors and patients with rheumatoid arthritis (RA) and ankylosing spondyloarthritis (AS) was carried out. When analyzing the alterations in hydrolase activity of the examined enzyme it was shown that in the blood lymphocytes of patients with RA and AS the primary active transport of Na+ and K+ ions is less intensive in comparison with practically healthy donors, but it is characterized by almost the same capacity as in donors. The affinity constant of Na+, K+ -ATPase for ATP in the blood lymphocytes in patients with RA and AS is greater 3.1 and 2.5 times, respectively, in comparison with healthy donor. It was found that in conditions of rheumatic pathology in immunocompetent cells 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. However, Mg2+ -binding center of Na+, K+ -ATPase in patients with RA and AS remains native. It was identified that the affinity constant of Na+, K+ -ATPase to Na+ ions in the blood lymphocytes of patients with RA and AS is 2.75 times lower than its value in healthy donors. Na+, K+ -ATPase of the blood lymphocytes of patients with RA and AS retains its native receptor properties and sensitivity to ouabain does not change.
Asunto(s)
Artritis Reumatoide/enzimología , Linfocitos/enzimología , Potasio/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Sodio/metabolismo , Espondilitis Anquilosante/enzimología , Adenosina Trifosfato/metabolismo , Sitio Alostérico , Artritis Reumatoide/patología , Estudios de Casos y Controles , Humanos , Hidrólisis , Transporte Iónico , Cinética , Linfocitos/efectos de los fármacos , Linfocitos/patología , Magnesio/metabolismo , Ouabaína/farmacología , Unión Proteica , Saponinas/farmacología , Espondilitis Anquilosante/patologíaRESUMEN
The analysis of the kinetic properties of Ca2+, Mg(2+)-ATPase of saponin-perforated peripheral blood lymphocytes of donors and patients with rheumatoid arthritis and ankylosing spondylitis was carried out. When analyzing the alterations in hydrolase activity of Ca2+, Mg(2+)-ATPase it was shown that affinity of Ca2+, Mg(2+)-ATPase of plasma membrane and membranes of endoplasmic reticulum for ATP do not significantly differ. It was found that the inhibition of examined enzyme systems occurs by mixed type both due to the reduction of maximum reaction rate and to the decrease of Ca2+, Mg(2+)-ATPase affinity for ATP in conditions of rheumatic pathology in the immunocompetent cells. It was identified that Ca2+, Mg(2+)-ATPase had significantly lower affinity for Ca2+ in lymphocytes of persons with rheumatic disorders than in donors.