title: [DNA double-strand breaks in human lymphocytes after single irradiation by low doses of pulsed X-rays: non-linear dose-response relationship].
abstract: Effects of ionizing radiation registered in cells after low dose irradiation are still poorly understood. A pulsed mode of irradiation is even more problematic in terms of predicting the radiation-induced response in cells. Thus, the aim of this paper was to study and analyze the effects of dose and frequency of pulsed X-rays on the frequency of radiation-induced DNA double-strand breaks and their repair kinetics in human peripheral blood lymphocytes in vitro. Analysis of radiation-induced gammaH2AX and 53BP1 repair foci was used to assess the DNA damage in these cells. The dose-response curve of radiation-induced foci of both proteins has shown deviations from linearity to a higher effect in the 12-32 mGy dose range and a lower effect at 72 mGy. The dose-response curve was linear at doses higher than 100 mGy. The number of radiation-induced gammaH2AX and 53BP1 foci depended on the frequency of X-ray pulses: the highest effect was registered at 13 pulses per second. Moreover, slower repair kinetics was observed for those foci induced by very low doses with a nonlinear dose-response relationship.
authors.forename: S A
authors.initials: SA
authors.lastname: Vasil'ev
authors.forename: E Iu
authors.initials: EIu
authors.lastname: Stepanova
authors.forename: O P
authors.initials: OP
authors.lastname: Kutenkov
authors.forename: A A
authors.initials: AA
authors.lastname: Belenko
authors.forename: L P
authors.initials: LP
authors.lastname: Zharkova
authors.forename: M A
authors.initials: MA
authors.lastname: Bol'shakov
authors.forename: I N
authors.initials: IN
authors.lastname: Lebedev
authors.forename: V V
authors.initials: VV
authors.lastname: Rostov
mesh_terms: D000483:Alleles; D002869:Chromosome Aberrations / Q000528:radiation effects*; D053903:DNA Breaks, Double-Stranded / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005838:Genotype; D006579:Heterozygote; D006657:Histones / Q000235:genetics / Q000528:radiation effects; D006720:Homozygote; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000528:radiation effects; D008214:Lymphocytes / Q000528:radiation effects*; D008297:Male; D000071857:Tumor Suppressor p53-Binding Protein 1; D014965:X-Rays
chemical_list: C468783:H2AX protein, human; D006657:Histones; D047908:Intracellular Signaling Peptides and Proteins; C498301:TP53BP1 protein, human; D000071857:Tumor Suppressor p53-Binding Protein 1