In vivo effects of chronic contamination with 137 cesium on testicular and adrenal steroidogenesis

Abstract

More than 20 years after Chernobyl nuclear power plant explosion, radionuclides are still mainly bound to the organic soil layers. The radiation exposure is dominated by the external exposure to gamma-radiation following the decay of (137)Cs and by soil-to-plant-to-human transfer of (137)Cs into the food chain. Because of this persistence of contamination with (137)Cs, questions regarding public health for people living in contaminated areas were raised. We investigated the biological effects of chronic exposure to (137)Cs on testicular and adrenal steroidogenesis metabolisms in rat. Animals were exposed to radionuclide in their drinking water for 9 months at a dose of 6,500 Bq/l (610 Bq/kg/day). Cesium contamination decreases the level of circulating 17beta-estradiol, and increases corticosterone level. In testis, several nuclear receptors messenger expression is disrupted; levels of mRNA encoding Liver X receptor alpha (LXRalpha) and LXRbeta are increased, whereas farnesoid X receptor mRNA presents a lower level. Adrenal metabolism presents a paradoxical decrease in cyp11a1 gene expression. In conclusion, our results show for the first time molecular and hormonal modifications in testicular and adrenal steroidogenic metabolism, induced by chronic contamination with low doses of (137)Cs.

The Metabolomic Approach Identifies a Biological Signature of Low-dose Chronic Exposure to Cesium 137

“…49) Moreover, these results confirmed the very low-dose range (0.004 Gy) of our study, consistent with results of similar experimental protocols carried out earlier in rats. [7][8][9][10]50,51) In addition, there was no imbalance in the proportions of blood cell types, such as that described in cases of high whole-body external irradiation (with a decrease white blood cells), 48,52) nor did we observe a change between the groups in hepatic, heart or kidney enzyme activity in plasma. Similarly, plasma lipid, protein and mineral concentrations did not change; such a change might have revealed a dysfunction or rupture in the organ or tissue integrity.…”

“…5) Experimental studies in rats chronically contaminated by 137 Cs, which is the most persistent radionuclide dispersed in this area (half-life of 30 years), have showed molecular and physiological effects in different metabolic pathways without, however, any major homeostatic deregulation. [7][8][9][10] Currently, analytical sensitivity is increasing with the use of new noninvasive methods. One of these is metabolomics, which appears useful 11) for finding specific biomarkers of chronic radiocesium exposure.…”

Absorbed radiation doses due to chronic ingestion of cesium-137 or strontium-90 by mice

“…This method of calculation using the DCF (ICRP, 2008) allows estimating in a simple and rapid way the mean body radiation doses absorbed by laboratory rodents in long-term contamination experiments, provided that biokinetic and organ mass data are available. These dose estimates have to be discussed in the context of previous results showing that chronic contamination through 137 Cs ingestion induced slight modifications of several physiological systems such as the cardiovascular system (Gueguen et al, ABSORBED RADIATION DOSES DUE TO CHRONIC INGESTION 2008), vitamin D metabolism (Tissandié et al, 2006) and steroid hormone metabolism (Grignard et al, 2008). Most of these modifications are variations in specific gene expression or protein concentrations.…”

“…For instance, chronic contamination with 137 Cs induced a modification of sleep-wake cycles in rats (Lestaevel et al, 2006), which may be associated with a neuroinflammatory reaction induced by the ingestion of radionuclides . Other modifications of physiological systems are also induced by 137 Cs ingestion such as the cardiovascular system , the vitamin D metabolism (Tissandié et al, 2006) and the steroid hormone metabolism (Grignard et al, 2008). However, most of the observed modifications are at the molecular level (such as gene expression modifications or variation in protein synthesis) without any pathological consequence on the health status of animals (Lestaevel et al, 2010).…”

Magnetic composites as an effective technology for removal of radioactive cesium

“…Cesium is water soluble and behaves similarly to potassium and sodium in a biological behavior profile. In addition, radioactive cesium can trigger negative health effects including carcinoma of the liver, kidney, bladder, renal function, cardiovascular disease, and gastrointestinal distress (Grignard et al 2008;Guéguen et al 2008;Souidi et al 2006). Matrices as several different polymers, zeolitelike materials, clay minerals, biomass, and metal oxides have previously been investigated for Cs removal (Gupta and Dubey 2005;Mercer and Ames 1978).…”