Molecular modifications of cholesterol metabolism in the liver and the brain after chronic contamination with cesium 137
Résumé
Twenty years after Chernobyl accident, the daily ingestion of foodstuff grown on contaminated grounds remains the main source for internal exposure to ionizing radiations, and primarily to cesium 137 (137Cs). Though the effects of a long-term internal contamination with radionuclides are poorly documented, several non-cancerous pathologies have been described in this population. However, lipid metabolism was never investigated after chronic internal contamination although disturbances were observed in externally-exposed people. In this regard, we assessed the effects of a chronic ingestion of 137Cs on hepatic and cerebral cholesterol metabolism. To mimic a chronically-exposed population, rats were given 137Cs-supplemented water at a post-accidental dose (150 Bq/rat/day) during 9 months. The plasma profile, and brain and liver cholesterol concentrations were unchanged. A decrease of ACAT 2, Apo E, and LXR < alpha > mRNA levels was recorded in the liver. In the brain, a decrease of CYP27A1 and ACAT 1 gene expression was observed. These results clearly show that cholesterol metabolism is not disrupted by a chronic ingestion of 137Cs, although several molecular alterations are observed. This work would be interestingly completed by studying the influence of 137Cs in models likely more sensitive to contaminants, such as the fetus or individuals susceptible to a lipidic disease. © 2009 Elsevier Ltd. All rights reserved.
Mots clés
- animal tissue
- Cholesterol Esters
- Gene Expression
- Health Status
- Liver
- Male
- Rats
- Sprague-Dawley
- Reverse Transcriptase Polymerase Chain Reaction
- Sterols
- Rattus
- Cholesterol
- animal experiment
- messenger RNA
- liver X receptor alpha
- cholesterol acyltransferase
- cholestanetriol 26 monooxygenase
- cesium 137
- apolipoprotein E
- metabolic disorder
- brain metabolism
- cholesterol blood level
- cholesterol metabolism
- controlled study
- diet supplementation
- fetotoxicity
- gene expression
- liver metabolism
- long term exposure
- male
- article
- molecular mechanics
- nonhuman
- nucleotide sequence
- rat
- Animals
- Brain Chemistry
- Carrier Proteins
- Cesium Radioisotopes
- Chernobyl Nuclear Accident