Chronic contamination with 137cesium in rat: Effect on liver cholesterol metabolism
Résumé
After the Chernobyl nuclear accident, epidemiological studies on human populations living in 137Cs-contaminated areas revealed the increase frequencies of thyroid cancer and evoked the apparition of cardiovascular diseases, hormonal effect, liver alteration, and lipid disorder. Actually, it raises a problem of public safety for the populations living on these territories that are exposed to low levels of 137Cs during a long period through food. Then it is necessary to study potential effect of this chronic contamination. To mimic this situation, the authors investigate the potential biological effects of chronic exposure to 137Cs at a postaccidental dose (150 Bq/rat/day) on hepatic metabolism of cholesterol in rat. Plasma lipid level, gene expression and activity were analyzed. It was observed that in 137Cs-exposed rats, gene expression of low-density lipoprotein receptor (LDLr), apolipoprotein B (apoB), and liver X receptor α (LXRα) are increased (95%, p < .05; 34%, p < .05; 20%, p < 0.05, respectively), whereas transporter adenosine triphosphate-binding cassette transporter G5 (ABCG5) is decreased (42%, p < .05). In addition, cytochrome P450 27A1 (CYP27A1) activity is increased (34%, p < .05) in contaminated rat liver. In conclusion, the results suggest that 137Cs contamination at low-level induces molecular modifications of the liver cholesterol metabolism without leading to a dysregulation of its homeostasis. These results suggest that chronic long term exposure at low-level of 137Cs may evolve to lipid disorder. Copyright © American College of Toxicology.
Mots clés
- ATP-Binding Cassette Transporters
- Male
- Liver
- Lipoproteins
- Gene Expression
- DNA-Binding Proteins
- Cytochrome P-450 CYP27A1
- Cholesterol 7-alpha-Hydroxylase
- Cholesterol
- Cesium Radioisotopes
- Microsomes
- Apolipoproteins B
- Animals
- Sprague Dawley rat
- metabolism
- liver mitochondrion
- liver microsome
- liver
- genetics
- gene expression
- hydroxymethylglutaryl coenzyme A reductase
- ABC transporter A1
- ABCG5 protein
- apolipoprotein B
- cesium 137
- cholestanetriol 26 monooxygenase
- cholesterol 7alpha monooxygenase
- cytochrome P450
- enzymology
- Messenger
- RNA
- LDL
- Cytoplasmic and Nuclear
- Receptors
- Sprague-Dawley
- Rats
- Mitochondria
- DNA binding protein
- cardiovascular disease
- article
- animal tissue
- animal model
- animal experiment
- animal cell
- messenger RNA
- liver X receptor
- lipoprotein
- chernobyl accident
- cholesterol
- cesium
- cell receptor
- rat
- Abcg5 protein
- ABC transporter
- sterol regulatory element binding protein
- low density lipoprotein receptor
- liver X receptor alpha
- male
- drug effect
- blood
- animal
- thyroid cancer
- receptor binding
- radioactive contamination
- radiation hazard
- nonhuman
- molecular biology
- lipid
- liver toxicity
- liver metabolism
- lipidosis
- gene expression regulation
- food contamination
- endocrine disease
- controlled study
- cholesterol metabolism