Chronic exposure to uranium leads to iron accumulation in rat kidney cells
Résumé
After it is incorporated into the body, uranium accumulates in bone and kidney and is a nephrotoxin. Although acute or short-term uranium exposures are well documented, there is a lack of information about the effects of chronic exposure to low levels of uranium on both occupationally exposed people and the general public. The objective of this study was to identify the distribution and chemical form of uranium in kidneys of rats chronically exposed to uranium in drinking water (40 mg uranium liter-1). Rats were killed humanely 6, 9, 12 and 18 months after the beginning of exposure. Kidneys were dissected out and prepared for optical and electron microscope analysis and energy dispersive X-ray (XEDS) or electron energy loss spectrometry (EELS). Microscopic analysis showed that proximal tubule cells from contaminated rats had increased numbers of vesicles containing dense granular inclusions. These inclusions were composed of clusters of small granules and increased in number with the exposure duration. Using XEDS and EELS, these characteristic granules were identified as iron oxides. Uranium was found to be present as a trace element but was never associated with the iron granules. These results suggested that the mechanisms of iron homeostasis in kidney could be affected by chronic uranium exposure. © 2007 by Radiation Research Society.
Mots clés
drinking water
iron
iron oxide
trace element
uranium
ferric ion
ferric oxide
animal cell
animal experiment
animal model
animal tissue
article
bioaccumulation
concentration (parameters)
controlled study
electron energy loss spectroscopy
environmental exposure
granular cell
homeostasis
kidney cell
kidney proximal tubule
male
microscopy
nonhuman
priority journal
rat
scanning electron microscope
X irradiation
animal
cell culture
cytology
dose response
drug effect
kidney
metabolic clearance rate
metabolism
oral drug administration
Sprague Dawley rat
tissue distribution
urine
water pollutant
Rattus
Administration
Oral
Animals
Cells
Cultured
Dose-Response Relationship
Drug
Ferric Compounds
Kidney
Kidney Tubules
Proximal
Male
Metabolic Clearance Rate
Rats
Sprague-Dawley
Tissue Distribution
Uranium
Water Pollutants
Radioactive