title: [Post-irradiation changes in blood 5'-nucleotidase activity of rats after chronic exposure to gamma irradiation].
abstract: Kinetics of 5'-AMP hydrolysis by rat's blood serum was studied at 3, 10, 30, 90 and 180 days after prolonged gamma-irradiation at 0.1-1 Gy doses (60Co source, dose rate 4.4 x 10(-6) Gy/h). It was shown that more expressed kinetic anticooperativity of nucleotidase reaction in irradiated animals, as compare to control ones, was conditioned by composition predominance of low-affinity 5'-nucleotidases forms over their high-affinity patterns. The ratio of maximal velocities of high- to low-affinity 5'-nucleotidases was ranged from 2 in the control to 7 in irradiated rats at different postirradiation periods during the first 90 days of observation. It was suggested that appearance of new kinetic 5'-nucleotidases forms in blood stream of irradiated animals, predominantly with low-affinity, was attributed to impairment in the integrity of cellular membranes and may testify to postirradiation development of tissues injury.
authors.affiliation: Institute of Radiobiology, National Academy of Sciences, Byelorussia, Minsk.
authors.forename: S M
authors.initials: SM
authors.lastname: Iakubovskiĭ
authors.forename: V N
authors.initials: VN
authors.lastname: Rybakov
mesh_terms: D015720:5'-Nucleotidase / Q000097:blood*; D000818:Animals; D003037:Cobalt Radioisotopes / Q000494:pharmacology; D005720:Gamma Rays; D006868:Hydrolysis; D007700:Kinetics; D008297:Male; D011829:Radiation Dosage; D011833:Radiation Injuries, Experimental / Q000097:blood / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D003037:Cobalt Radioisotopes; D015720:5'-Nucleotidase