Purine metabolizing enzyme activities in radiosensitive tissues of mice after sublethal whole-body irradiation.
The activities of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) were determined between days 1-14 in the spleen, thymus and femoral bone marrow of mice subjected to whole-body gama irradiation with a dose of 5.5 Gy. In control animals, the highest activity of ADA (as related to 10(6) cells) was recorded in the thymus (58.9 pmol.s-1), the lowest one in the femur (34.8 pmol.s-1), the PNP activity was the lowest in the thymus (14.5 pmol.s-1) and the highest in the femur (96.0 pmol.s-1). In the spleen, an elevation of ADA activity (up to 379%) was observed during the first postirradiation days; PNP activity was reduced (to 58%) on postirradiation day 3, followed by the return and even elevation on day 14 (265%). In the thymus, a parallel reduction of the activities of both enzymes appeared during the first postirradiation days, with a subsequent increase during the regeneration phase. In the femoral bone marrow, ADA and PNP activities were increased on postirradiation day 1 (275% and 201%, respectively). Reference is made to the possible relationship between the observed characteristic changes in activities and the degree of damage and/or renewal of cell population in the hemopoietic tissues after irradiation.
Hosek
B
B
Institute of Biophysics, Czechoslovak Academy of Sciences, Brno.
Bohácek
J
J
Sikulová
J
J
D000243:Adenosine Deaminase / Q000378:metabolism / Q000528:radiation effects*; D000818:Animals; D001853:Bone Marrow / Q000201:enzymology / Q000528:radiation effects; D007700:Kinetics; D051379:Mice; D008815:Mice, Inbred Strains; D009700:Nucleoside Deaminases / Q000528:radiation effects*; D009928:Organ Specificity; D010430:Pentosyltransferases / Q000528:radiation effects*; D011683:Purine-Nucleoside Phosphorylase / Q000378:metabolism / Q000528:radiation effects*; D011687:Purines / Q000378:metabolism*; D012016:Reference Values; D013154:Spleen / Q000201:enzymology / Q000528:radiation effects; D013950:Thymus Gland / Q000201:enzymology / Q000528:radiation effects; D014916:Whole-Body Irradiation
D011687:Purines; D010430:Pentosyltransferases; D011683:Purine-Nucleoside Phosphorylase; D009700:Nucleoside Deaminases; D000243:Adenosine Deaminase