Studies carried out within the scope of the ENVIRHOM research programme have highlighted biological effects on various metabolisms following the chronic ingestion of caesium 137 (137Cs) or uranium.
We have suggested that these radionuclides could affect certain metabolic pathways in numerous ways but to minor extent, thus generating subtle biological effects. A global analysis of the metabolites via a metabolomic approach therefore seems relevant in order to determine the biological extent of chronic internal exposure at low dose of radionuclide. The identification of the molecular targets could thus create specific metabolic signature of such exposures. Metabolomics provides a detailed description of the metabolite composition of biofluids (blood, urine) using a powerful analytical platform employing techniques such as liquid chromatography coupled to mass spectrometry. The data obtained are processed using methods of multivariate statistical analysis and can identify the early and sensitive biomarkers of toxicity and pathologies. This technique was primarily used in medicine, toxicology and pharmacology. Metabolomics is a link between genotype and phenotype. This approach is complementary to genomic and transcriptomic methods, which are insufficient for describing and explaining phenotypes.
A metabolomic study was therefore launched with a scientific collaboration between the laboratoire de Nutriments Lipidiques et Prévention des Maladies Métaboliques (Université Aix-Marseilles I and II - Laboratory for Lipid Nutrients and the Prevention of Metabolic Diseases) and the IRSN. This is the first study that combined metabolomics and radiotoxicology in an in-vivo model. This partnership focused on studying the effects of the daily ingestion of 150 Bq caesium 137 by rats for 9 months via drinking water (6500 Bq.L-1), which corresponds to post-accident environmental contamination comparable to that recorded around Chernobyl following the accident in 1986.
The results of this experimental study will establish whether chronic contamination with caesium 137 triggers a specific metabolic signature allowing to discriminate 137Cs-contaminated from control animals. In addition, this will identify the metabolic pathways sensitive to this radionuclide, thus highlighting its toxicological effects.