Uranium Microdistribution in Renal Cortex of Rats after Chronic Exposure: A Study by Secondary Ion Mass Spectrometry Microscopy

Abstract

For a few years, the biological effects on ecosystems and the public of the bioaccumulation of radionuclides in situations of chronic exposures have been studied. This work, in keeping with the ENVIRHOM French research program, presents the uranium microdistribution by secondary ion mass spectrometry (SIMS) technique in the renal cortex of rats following chronic exposure to this low level element in the drinking water (40 mg/L) as a function to exposure duration (6, 9, 12, and 18 months). The SIMS mass spectra and 238U+ ion images produced with a SIMS CAMECA 4F-E7 show the kinetic of uranium accumulation in the different structures of the kidney. For the rats contaminated up to 12 months, the radioelement is mainly fixed in the proximal tubules; then after 18 exposure months, uranium is detected in all the segments of the nephron. This work has also shown that ion microscopy is an analytical method to detect trace elements and give elemental cartography at the micrometer scale.

A novel calibration strategy based on internal standard–spiked gelatine for quantitative bio-imaging by LA-ICP-MS: application to renal localization and quantification of uranium

“…These results show up the ascendant concentration of uranium from the medulla to cortex by a factor of 120, which is in agreement with the quantitative results obtained by high-energy synchrotron radiation X-ray fluorescence (SR-XRF) analysis published by Homma-Takeda [16]. Additionally, the fact that the uranium accumulates at greater concentrations in the renal cortex is also corroborated by a previous study carried out by Tessier et al employing secondary ion mass spectrometry (SIMS) microscopy [61].…”

Intracellular uranium distribution: Comparison of cryogenic fixation versus chemical fixation methods for SIMS analysis

“…This observation could be documented by a lesser binding to the macromolecules within the cytoplasm (Bresson et al, ; Frelon, Mounicou, Lobinski, Gilbin, & Simon, ; Ortega et al, ; Perrin, Carmona, Roudeau, & Ortega, ). In addition, we have previously shown from in vivo experiments i using SIMS microscopy that uranium is heterogeneously distributed in the nephron and localized mainly in cell nuclei of proximal convoluted tubules (Poisson et al, ; Tessier et al, ). Similar uranium distribution has been observed using different imaging technic in case of acute renal contamination in rats (Homma‐Takeda et al, ).…”

“…SIMS microscopy analyzes the elemental and isotopic composition of a solid surface through an ion beam coupled with a mass spectrometer. The principle of this technique has been previously described by Rouas et al () and Tessier et al (). The SIMS analyses were performed with a CAMECA IMS 4F E7 instrument.…”

Metabolomics reveals dose effects of low-dose chronic exposure to uranium in rats: identification of candidate biomarkers in urine samples

“…Recently, NMN was proposed as an endogenous probe for the evaluation of organic cation secretion in proximal tubules and of drug interactions with renal organic cation transporters (Ito et al 2012 ; Müller et al 2015 ). Moreover, uranium ingested chronically through drinking water at a dose of 40 mg L −1 accumulates primarily in the proximal tubules during the first 12 month and thereafter can be detected in all other segments of the nephron (Tessier et al 2012 ). Finally, it has been reported that a single high dose of uranium (10 mg kg −1 in rats) causes structural damage to the renal proximal tubules (Haley et al 1982 ).…”