title: [Changes induced by low doses of ionizing radiation in the accessibility to DNA restriction enzymes of the ribosomal gene system of human lymphocytes].
abstract: Human lymphocytes were X-irradiated at doses 0-10(-2) Gy and allowed to repair for some time. Nuclei were prepared and digested with restriction endonuclease Rsa I to selectively release 28S RNA gene fragment fraction, containing the DNA-binding protein, Hpa II digestion of nuclei was used to investigate the methylation of the 28S RNA gene fragment. There was a differential enrichment of 28S RNA gene binding protein for different X-ray doses with maximum enrichment for dose 2-3 x 10(-2) Gy with following diminish to 10 x 10(-2). The enrichment of less methylated fractions of 28S RNA gene was observed during X-irradiation. This might be explained by a different X-ray-induced changes of methylated and unmethylated rDNA binding with nuclear proteins. The possible mechanism for this phenomena are discussed.
authors.forename: N N
authors.initials: NN
authors.lastname: Veĭko
authors.forename: D M
authors.initials: DM
authors.lastname: Spitkovskiĭ
mesh_terms: D001798:Blood Proteins / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D002478:Cells, Cultured; D019175:DNA Methylation / Q000528:radiation effects; D004262:DNA Restriction Enzymes / Q000494:pharmacology*; D004275:DNA, Ribosomal / Q000097:blood / Q000187:drug effects / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D011485:Protein Binding / Q000528:radiation effects; D012339:RNA, Ribosomal, 28S / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*
chemical_list: D001798:Blood Proteins; D004275:DNA, Ribosomal; D012339:RNA, Ribosomal, 28S; D004262:DNA Restriction Enzymes