[Changes in the lymphoid cells of DNA and purine nucleotide synthesis and sensitivity to glucocorticoids associated with impairment of differentiation and immune function during tumor growth in mice. Thymocytes].
Some biochemical mechanisms underlying the impairments of cellular immunity were studied in C3Ha mice in the course of growth of transplantable and induced (ortoaminoazotoluol) solid hepatomas. During intensive hepatoma growth, the adenosine deaminase activity in host thymocytes was shown to be drastically (6 times) reduced, resulting in the elevation of dATP and dGTP concentrations (6- and 7-fold, respectively), the potential inhibitors of ribonucleoside diphosphate reductase. Consequently, the rate of DNA synthesis was reduced as can be evidenced by the decrease of (a) thymidine kinase activity, (b) 14C-thymidine incorporation into DNA, and (c) dTTP and dCTP pools. By the terminal period of hepatoma growth (both transplantable and induced one), the serum corticosterone content increased 3- and 8-fold, respectively. At the same time, specific binding of [3H]triamsinolone acetonide by thymocytes was augmented and the activity of terminal deoxynucleotidyl transferase increased the latter alterations, which can be regarded as a reflection (including other parameters mentioned) of the arrest of T-lymphocyte differentiation at the level of immature cortex thymocytes.
Potapova
G I
GI
Khramtsova
S N
SN
Dmitrieva
L V
LV
Shapot
V S
VS
D000243:Adenosine Deaminase / Q000378:metabolism; D000818:Animals; D003345:Corticosterone / Q000097:blood*; D004253:DNA Nucleotidylexotransferase / Q000378:metabolism; D004273:DNA, Neoplasm / Q000096:biosynthesis*; D007108:Immune Tolerance; D007111:Immunity, Cellular; D007114:Immunization; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008809:Mice, Inbred C3H; D011685:Purine Nucleotides / Q000378:metabolism*; D011683:Purine-Nucleoside Phosphorylase / Q000378:metabolism; D013601:T-Lymphocytes / Q000201:enzymology / Q000276:immunology* / Q000378:metabolism
D004273:DNA, Neoplasm; D011685:Purine Nucleotides; D011683:Purine-Nucleoside Phosphorylase; D004253:DNA Nucleotidylexotransferase; D000243:Adenosine Deaminase; D003345:Corticosterone
Izmeneniia v limfoidnykh kletkakh sinteza DNK, purinovykh nukleotidov i chuvstvitel'nosti k gliukokortikoidam, sopriazhennye s narusheniem differentsirovki i immunnoĭ funktsii u mysheĭ v protsesse opukholevogo rosta. Timotsity.