Chronic contamination of rats with 137cesium radionuclide: Impact on the cardiovascular system
Résumé
Cardiovascular system impairment has been observed in children and in liquidators exposed to the Chernobyl nuclear power plant accident. No experimental studies of animals have analyzed whether these disorders might be attributed to chronic ingestion of low levels of cesium 137 (137Cs). Biochemical, physiological, and molecular markers of the cardiovascular system were analyzed in rats exposed through drinking water to 137Cs at a dose of 500 Bq kg-1 (6500 Bq l-1). Plasma concentrations of CK and CK-MB were higher (+52%, P < 0.05) in contaminated rats. No histological alteration of the heart was observed, but gene expression was modified in the atria. Specifically, levels of ACE (angiotensin converting enzyme) and BNP (brain natriuretic peptide) gene expression increased significantly (P < 0.05). ECG analysis did not disclose any arrhythmia except ST- and RT-segment shortening (-9% and -11%, respectively, P < 0.05) in rats exposed to 137Cs. Mean blood pressure decreased (-10%, P < 0.05), and its circadian rhythm disappeared. Overall, chronic contamination by an extreme environmental dose of 137Cs for 3 months did not result in cardiac morphological changes, but the cardiovascular system impairments we observed could develop into more significant changes in sensitive animals or after longer contamination. © 2008 Humana Press.
Mots clés
brain natriuretic peptide
cesium 137
creatine kinase
dipeptidyl carboxypeptidase
drinking water
animal experiment
article
blood pressure
cardiovascular system
circadian rhythm
controlled study
creatinine blood level
electrocardiography
gene expression
heart atrium
histology
male
nonhuman
priority journal
radioactive contamination
rat
statistical significance
Animals
Cesium Radioisotopes
Chernobyl Nuclear Accident
Creatine Kinase
MB Form
Environmental Exposure
Gene Expression
Heart
Heart Atria
Heart Conduction System
Male
Myocardium
Natriuretic Peptide
Brain
Peptidyl-Dipeptidase A
Radioactive Pollutants
Rats
Sprague-Dawley
RNA
Messenger
Tachycardia
Animalia
Rattus