Formation peculiarities of radiation-induced aberrations of chromosomes in human cells under the modifying influence of chemical agents (comparative aspects).

OBJECTIVE: The study objective was to determine and provide a comparative analysis of frequency and spectrum of the induced aberrations of chromosomes in culture of the human peripheral blood lymphocytes under the combined impact of radiation, co-mutagen, and chemical mutagen. METHODS: Culture of human peripheral blood lymphocytes and cytogenetic methods have been used. RESULTS: A co-mutagenic effect of the drug verapamil was established under the testing γ-irradiation of human peripheral blood lymphocytes in the dose range of 0.3-2.0 Gy at the expense of increased frequency of chromosomal aberrations (dicentrics). The combined effect of γ-irradiation and S-Nitrosoglutathione is directed on the induction and storage of chemical markers of exposure - the chromatid-type aberrations. CONCLUSION: A co-mutagenic effect of verapamil under the low-dose γ-irradiation as a 2-fold increase of the chromosome-type aberrations (radiation markers) incidence was revealed at a chromosomal level in human peripheral blood lymphocytes. Phenomenon of synergism of low-dose γ-irradiation and mutagen S-Nitrosoglutathione as a ~3-fold increased frequency of chromatid-type aberrations (chemical markers) was detected compared to the sole radiation effect.

Increased individual chromosomal radiosensitivity of human lymphocytes as a parameter of cancer risk.

AIM: Evaluation of chromosomal radiosensitivity of healthy individuals and determination those with the increased susceptibility to radiogenic cancer. METHODS: Cytogenetic examination of radiation induced injuries in lymphocytes of healthy individuals (n=103) was carried out on the basis of G(2)-assay. Test system of peripheral blood lymphocytes with metaphase analysis was used. RESULTS: On the basis of the obtained "stage-effect" and "dose-effect" calibrating curves the scheme of cytogenetic examinations of healthy individuals was developed. Analysis of cytogenetic parameters induced by G(2) irradiation at 1.5 Gy dose revealed their high interindividual variability. The highest differences were registered for chromatid type aberrations (CV=42.1%) with the chromatid break predominance in the spectrum (CV=37.5%). Statistical analysis of the distributions of the obtained individual cytogenetic parameters indicated 12% individuals with increased chromosomal radiosensitivity. CONCLUSIONS: Cytogenetic evaluation of individual chromosomal radiosensitivity based on G(2)-assay has its perspectives in the formation of groups with increased risk of radiogenic cancer developing and its primary prophylactics among healthy population.