Molecular modifications of cholesterol metabolism in the liver and the brain after chronic contamination with cesium 137.
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 ((137)Cs). 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 (137)Cs on hepatic and cerebral cholesterol metabolism. To mimic a chronically-exposed population, rats were given (137)Cs-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 (137)Cs, although several molecular alterations are observed. This work would be interestingly completed by studying the influence of (137)Cs in models likely more sensitive to contaminants, such as the fetus or individuals susceptible to a lipidic disease.
Racine
R
R
Institute for Radiological Protection and Nuclear Safety (IRSN), Radiological Protection and Human Health Division, Radiobiology and Epidemiology Department, Laboratory of Experimental Toxicology, BP No. 17, F-92262 Fontenay-aux-Roses Cedex, France.
Grandcolas
L
L
Grison
S
S
Gourmelon
P
P
Guéguen
Y
Y
Veyssière
G
G
Souidi
M
M
D000818:Animals; D001923:Brain Chemistry / Q000528:radiation effects*; D002352:Carrier Proteins / Q000378:metabolism; D002588:Cesium Radioisotopes / Q000009:adverse effects; D047852:Chernobyl Nuclear Accident; D002784:Cholesterol / Q000378:metabolism*; D002788:Cholesterol Esters / Q000378:metabolism; D015870:Gene Expression / Q000235:genetics / Q000528:radiation effects; D006304:Health Status; D008099:Liver / Q000378:metabolism* / Q000528:radiation effects*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013261:Sterols / Q000097:blood
D002352:Carrier Proteins; D002588:Cesium Radioisotopes; D002788:Cholesterol Esters; D013261:Sterols; D002784:Cholesterol