Estatus de parámetros oxidativos y del gen p53 en sangre de niños en edad escolar de zonas afectadas por el accidente nuclear de Chernobyl.

Abstract

After the nuclear accident of Chernobyl on April 26, 1986, the release of a large amount of radioisotopes contaminated the environment, with the subsequent consequences to the health of the people affected. The irradiation by means of its indirect mechanism on biological material led to an increase of oxygen-free radicals and therefore to a state of oxidative stress, which is directly involved in the alteration of oncogenes and tumor suppressor genes and therefore in the appearance of cancer. This research work has been carried out with a group of 310 children from different cities of Ukraine (Slavutich, Bucha-Irpen and Kiev) within a range of 125 km from the place of the Chernobyl accident. These children lived with Valencian host families between 1994 and 1997, under the Program "Ucrania 2000" organized by the Spanish NGO "Abogados sin fronteras". All the children underwent medical examination in the Childrens Department of Oncohematology of the Valencian University Clinical Hospital, including a detailed clinical report and a clinical, nutritional and analytical evaluation. Karyotype determination was conducted with a group of them. During 1996 and 1997, blood samples were collected and sent to the Department of Biochemistry and Molecular Biology of the Faculty of Medicine of Valencia to study oxidative stress and gene p53. The analysis of oxidative stress included the determination of antioxidant enzymes: catalase and superoxide dismutase; antioxidant substrate: reduced glutathione; marker for lipid peroxidation: malondialdehyde; and the modified base 8-oxo-2 deoxyguanosine. Following the clinical-analytical evaluation, no case of cancer was detected during the period of this research and no haematological alterations, nor any case of clinical primary hypothyroidism was observed either. In the study of oxidative stress, reduced glutathione has been positively related with the distance to the place of the accident; observing higher values in those children from closer areas. No point mutations have been detected in gene p53. In the cytogenetic study, chromosome alterations have been found without clinical expression. However, the appearance or development of future pathological processes cannot be disregarded.