Volume 5, Number 1, pp. 21-24
Influence of 6-ketocholestanol on structural-dynamic and functional characteristics of immunocompetent cells
N. Migineishvili, N. Kobakhidze and N. Sultanishvili
Iv. Javakhishvili Tbilisi State University, Chair of Biophysics, Department of Biology, 10 Gamrekeli St, 0186 Tbilisi, Georgia
The marked effects of elevated concentrations of the secondary oxidative product of cholesterol, 6-ketocholestanol, on rat liver lymphocyte membrane fluidity, membrane-bound lipid-dependent enzyme activity (5-nucleotidase, glucose-6-phosphatase and acid phosphatase) and Na+, K+ permeability (Na+, K+-ATPase activity and total ion flow) have been investigated. Its incorporation into membranes increases the fluidity of the membrane bilayer (measured by the change of fluorescence polarization from the fluorescent probe 1,8-ANS). Permeability is apparently much more increased for K+ than for Na+ ions. Na+ and K+-ATPase activity was determined for all concentrations investigated. A concentration-dependent effect of ketocholestanol upon diversely localized enzyme activity has been observed.
Keywords: fluidity, lymphocyte, membrane-bound enzymes, permeability, 6-ketocholestanol