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
Rats
Sprague-Dawley
Reverse Transcriptase Polymerase Chain Reaction
Sterols
Rattus
apolipoprotein E
cesium 137
cholestanetriol 26 monooxygenase
cholesterol acyltransferase
liver X receptor alpha
messenger RNA
animal experiment
animal tissue
article
brain metabolism
cholesterol blood level
cholesterol metabolism
controlled study
diet supplementation
fetotoxicity
gene expression
liver metabolism
long term exposure
male
metabolic disorder
molecular mechanics
nonhuman
nucleotide sequence
rat
Animals
Brain Chemistry
Carrier Proteins
Cesium Radioisotopes
Chernobyl Nuclear Accident
Cholesterol
Cholesterol Esters
Gene Expression
Health Status
Liver
Male