title: [Study of stability of lactate dehydrogenase isoenzymes in leucocytes of elderly people].
abstract: In this paper was investigated stability of isoenzymes of lactatdehydrogenase (LDH) of leukocytes of peripheral blood of persons at the age of 20 years (n=10) and more than 65 years (n=8). Extraction of the leukocytes was conducted by centrifugation of human blood on a double gradient of density. Leukocytes were destroyed by hypotonic shock in combination with vibration. Separation of LDH isoenzymes from destroyed leukocytes was conducted by the method of native electrophores. The revealing of activity of LDH isoenzymes was conducted by the method of restoration of nitroblue tetrasolium. Isoenzymes stability was evaluated according to alteration of activity after the incubation of destroyed leukocytes with urea in various concentrations (1M, 2M and 3M). Was shown the presence of three isoenzymes of LDG (LDH-1, LDH-2, LDH-3) in human leukocytes. As the age-dependent alteration of activity of isoenzymes of lactatdehydrogenase in human leukocytes was shown. It can be caused by age-related changes of physico-chemical properties of leukocytes' membranes and/or isoenzymes stability. Stability of LDH-3 was decreased with the age. Observed decrease of LDH-3 stability can be caused by age-related modification of M-subunits of the studied isoenzymes.
authors.forename: M V
authors.initials: MV
authors.lastname: Kuskov
authors.forename: S A
authors.initials: SA
authors.lastname: Afanas'ev
authors.forename: A N
authors.initials: AN
authors.lastname: Repin
authors.forename: V V
authors.initials: VV
authors.lastname: Potanina
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000097:blood*; D004795:Enzyme Stability / Q000187:drug effects; D006801:Humans; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D007962:Leukocytes / Q000187:drug effects / Q000201:enzymology*; D014508:Urea / Q000494:pharmacology
chemical_list: D007527:Isoenzymes; D014508:Urea; D007770:L-Lactate Dehydrogenase