Contamination chronique par le césium 137: effet sur le système cardiovasculaire

Titre du congrès :EUROTOX 2007
Ville du congrès :Amsterdam
Date du congrès :07/10/2007

Titre de la revue : Toxicology Letters Volume 172 Supplément 1 Page S5

  Following the accident at the Chernobyl Nuclear Power plant, a marked increase of various diseases was reported in the literature. Impairments of the cardiovascular system have been observed in children and in liquidators, however no experimental studies were undertaken on animals to analyse if these disorders could be attributed to the chronic ingestion of low levels of cesium 137 (137Cs).
Biochemical, physiological and molecular markers of the cardiovascular system were analysed in rats exposed through drinking water to 137Cs at a dose of 500 Bq/kg (6500 Bq/l). Plasma concentration of CK and CK-MB, biochemical markers of cardiac damage, were higher (+52%, p<0.05) in contaminated rats whereas no histological alteration of the heart appeared. Nevertheless, small modifications of heart gene expression were observed in the atria. ACE (angiotensin converting enzyme), the rate-limiting enzyme of the renin-angiotensin system, and BNP (brain natriurectic peptide), involved in physiological regulation of blood pressure, were significantly increased (p<0.05). ECG and blood pressure measurement were then undertaken to analyse if there were any physiological consequences. No arrhythmia was observed except ST- and RT segment shortening (-9% and -11% respectively, p<0.05) in rats exposed to 137Cs. Furthermore, mean arterial blood pressure decreased (–10%, p<0.05) in 137Cs-exposed rats along with a disappearance of the blood pressure circadian rhythm.
Overall, chronic contamination with extreme environmental dose of 137Cs during three months didn't result in pathological disorder, but the impairments of the cardiovascular system observed could evolve to more significant alteration in sensitive animals or after a longer contamination.