title: Inhibition of deamination of 14C-cytosine arabinoside (NSC-63878): a useful biologic assay for tetrahydrouridine (NSC-112907).
abstract: Inhibition of the deamination of 14C-cytosine arabinoside by two lots of tetrahydrouridine was studied in monkey serum. The average inhibition of deaminase activity was 78% for tetrahydrouridine lot AJ39 (1.0 muM) when the concentration of cytosine arabinoside ranged from 44.2 to 170.7 muM; under the same conditions tetrahydrouridine lot AJ22 inhibited deamination by an average of 68%. Apparent Ki values were 0.26 muM for AJ39 and 0.43 muM for AJ22. The assay may be used to check the relative biologic activity of various lots of tetrahydrouridine.
mesh_terms: D000818:Animals; D003561:Cytarabine / Q000378:metabolism*; D003641:Deamination; D003864:Depression, Chemical; D000882:Haplorhini; D007700:Kinetics; D013767:Tetrahydrouridine / Q000494:pharmacology; D014529:Uridine / Q000031:analogs & derivatives*
chemical_list: D003561:Cytarabine; D013767:Tetrahydrouridine; D014529:Uridine