Chronic contamination of rats with 137 cesium radionuclide: impact on the cardiovascular system.
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 ((137)Cs). Biochemical, physiological, and molecular markers of the cardiovascular system were analyzed in rats exposed through drinking water to (137)Cs 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 (137)Cs. Mean blood pressure decreased (-10%, P < 0.05), and its circadian rhythm disappeared. Overall, chronic contamination by an extreme environmental dose of (137)Cs 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.
Guéguen
Yann
Y
Institut de Radioprotection et de Sûreté Nucléaire, Direction de la RadioProtection de l'Homme, Service de Radiobiologie et d'Epidémiologie, Laboratoire de RadioToxicologie Expérimentale, IRSN, Fontenay-aux-Roses Cedex, France. yann.gueguen@irsn.fr
Lestaevel
Philippe
P
Grandcolas
Line
L
Baudelin
Cédric
C
Grison
Stéphane
S
Jourdain
Jean-René
JR
Gourmelon
Patrick
P
Souidi
Maâmar
M
D000818:Animals; D002588:Cesium Radioisotopes / Q000633:toxicity*; D047852:Chernobyl Nuclear Accident; D052279:Creatine Kinase, MB Form / Q000097:blood; D004781:Environmental Exposure / Q000009:adverse effects; D015870:Gene Expression / Q000187:drug effects; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects / Q000378:metabolism; D006329:Heart Conduction System / Q000187:drug effects / Q000503:physiopathology; D008297:Male; D009206:Myocardium / Q000473:pathology; D020097:Natriuretic Peptide, Brain / Q000235:genetics / Q000378:metabolism; D007703:Peptidyl-Dipeptidase A / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011848:Radioactive Pollutants / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013610:Tachycardia / Q000139:chemically induced / Q000503:physiopathology
D002588:Cesium Radioisotopes; D012333:RNA, Messenger; D011848:Radioactive Pollutants; C495963:natriuretic peptide precursor type B, rat; D020097:Natriuretic Peptide, Brain; D052279:Creatine Kinase, MB Form; D007703:Peptidyl-Dipeptidase A