title: [Ribonucleotide reductase--a "target" of the action of nitrosomethylurea].
abstract: The antitumor and toxic effects of methylnitrosourea (MNU) are determined through its metabolic pathways. In organism MNU is subject to hydrolytic decomposition and denitrosation. It has been shown in vivo studies that MNU abdominal injections of therapeutic doses caused the inhibition of ribonucleotide reductase in mouse spleen, and therefore the DNA synthesis depress. The effect may apparently contribute to antitumor property of MNU. It has been estimated that destruction of M2 subunit of the enzyme is occurred. The relation between the loss of ribonucleotide reductase activity and the inhibition of protein synthesis was discussed. Besides, the cancerogenic and mutagenic properties of MNU were discussed as a result of imbalance of DNA precursor pools. Changes in contents of Fe(3+)-transferrin, ceruloplasmin, methemoglobin in blood and spleen of animals after MNU injections have been found. The changes were reversible after single MNU injection and became irreversible after multiple injections.
authors.forename: D E
authors.initials: DE
authors.lastname: Filatov
authors.forename: M E
authors.initials: ME
authors.lastname: Kudriavtsev
authors.forename: L M
authors.initials: LM
authors.lastname: Baĭder
authors.forename: V L
authors.initials: VL
authors.lastname: Sharygin
authors.forename: K V
authors.initials: KV
authors.lastname: Griakalov
authors.forename: M K
authors.initials: MK
authors.lastname: Pulatova
authors.forename: D B
authors.initials: DB
authors.lastname: Korman
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002384:Catalysis; D004247:DNA / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004578:Electron Spin Resonance Spectroscopy; D008770:Methylnitrosourea / Q000494:pharmacology*; D051379:Mice; D012264:Ribonucleotide Reductases / Q000037:antagonists & inhibitors / Q000187:drug effects*; D013154:Spleen / Q000187:drug effects / Q000201:enzymology; D013997:Time Factors
chemical_list: D008770:Methylnitrosourea; D004247:DNA; D012264:Ribonucleotide Reductases
vernacular_title: Ribonukleotidreduktaza--"mishen'" deĭstviia nitrozometilmocheviny.