Rubidium Distribution in Kidneys of Immature Rats

Homma-Takeda, Shino; Terada, Yasuko; Iso, Hiroyuki; Ishikawa, Takahiro; Oikawa, Masakazu; Konishi, Teruaki; Imaseki, Hitoshi; Shimada, Yoshiya

doi:10.1142/s0129083509001722

Cited by 13 publications

(9 citation statements)

References 16 publications

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“…For example, elemental contents in each nephron unit would be provided when the quantitative local analysis is employed for renal tissue specimens. It has been demonstrated the complementary dynamics between P and S in spermatogenesis, 9 the different distribution between K and Rb, a K cogener in renal tubules, 18 and the interaction of light elements with toxic metal, such as cysteine residues with mercury or cadmium, 19,20 and phosphate with uranium. 21 Therefore, the quantitative local analysis using thin section standards would be a useful technique for the biomedical studies for light elements.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of Thin Section Standards for Local Analysis of Light Elements by Micro-Pixe Analysis

Homma-Takeda¹,

Suzuki

Harumoto

et al. 2011

Int. J. PIXE

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For quantitative measurements of light elements by micro-PIXE (particle-induced X-ray emission) analysis, suitable external standards have been expected. In this paper thin sections of polyvinyl alcohol solution containing phosphorus (P) and potassium (K) were assessed for their purpose as standards by micro-PIXE analysis. Homogeneity of P and K added to the standard materials were validated by 1 µm and 10 µm-step scanning of the standard. The relative standard deviations of the X-ray intensity of the standards P and K were < 25% and <16%, respectively. The calibration line between the X-ray intensity obtained from a 100 ×100 µm 2 area and the elements concentration was also acceptable, indicating that the thin section standards are adequate for an external standard of micro-PIXE measurements for light elements.

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Section: Resultsmentioning

confidence: 99%

Evaluation of Thin Section Standards for Local Analysis of Light Elements by Micro-Pixe Analysis

Homma-Takeda¹,

Suzuki

Harumoto

et al. 2011

Int. J. PIXE

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“…Briefly, X-ray intensity data of the U Lβ2 were obtained by scanned 1 μm × 1 μm areas of the specimens under conditions of proton energy of 3.0 MeV and integrated current of 0.2 μC with 1 μm × 1 μm spatial resolution. We detected the Lβ2 line for quantitative determination because endogenous renal rubidium [24] interferes with detection of the uranium Lα line. Uranium in microregions was quantified using thin section standards of uranium for microbeam analysis (10 µm; 0–500 μg·g −1 ) [25].…”

Section: Methodsmentioning

confidence: 99%

Phosphorus Localization and Its Involvement in the Formation of Concentrated Uranium in the Renal Proximal Tubules of Rats Exposed to Uranyl Acetate

Homma-Takeda

Numako

Kitahara

et al. 2019

IJMS

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Although the kidneys comprise a critical target of uranium exposure, the dynamics of renal uranium distribution have remained obscure. Uranium is considered to function physiologically in the form of uranyl ions that have high affinity for phosphate groups. The present study applied microbeam-based elemental analysis to precisely determine the distribution of phosphorus and uranium in the kidneys of male Wistar rats exposed to uranium. One day after a single subcutaneous injection of uranyl acetate (2 mg/kg), areas of concentrated phosphorus were scattered in the S3 segments of the proximal tubule of the kidneys, whereas the S3 segments in control rats and in rats given a lower dose of uranium (0.5 mg/kg) contained phosphorus without concentrated phosphorus. Areas with concentrated phosphorus contained uranium 4- to 14-fold more than the mean uranium concentration (126–472 vs. 33.1 ± 4.6 μg/g). The chemical form of uranium in the concentrated phosphorus examined by XAFS was uranium (VI), suggesting that the interaction of uranyl ions with the phosphate groups of biomolecules could be involved in the formation of uranium concentration in the proximal tubules of kidneys in rats exposed to uranium.

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“…SR‐XRF measurements of the uranium concentration were carried out at the SPring‐8 laboratory at the Japan Synchrotron Radiation Research Institute, Hyogo, using an energy dispersive SR‐XRF system with 30 keV monochromatic X‐rays (Terada et al ., ). For uranium mapping, the X‐ray intensity data for each point of the uranium Lβ lines (peak width = 16.1–17.6 keV) were processed using a personal computer because renal endogenous rubidium (Homma‐Takeda et al ., ) interfered with detection of the uranium Lα line. Elemental maps are shown as tones ranging from black to white, classified into 256 degrees from 10 µg g –1 (the lower detection limit) up to the maximum concentration in linear proportion to element concentration.…”

Section: Methodsmentioning

confidence: 99%

Uranium dynamics and developmental sensitivity in rat kidney

Homma-Takeda¹,

Kokubo²,

Terada

et al. 2013

J of Applied Toxicology

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Renal toxicity is the principal health concern after uranium exposure. Children are particularly vulnerable to uranium exposure; with contact with depleted uranium in war zones or groundwater contamination the most likely exposure scenarios. To investigate renal sensitivity to uranium exposure during development, we examined uranium distribution and uranium-induced apoptosis in the kidneys of neonate (7-day-old), prepubertal (25-day-old) and adult (70-day-old) male Wistar rats. Mean renal uranium concentrations increased with both age-at-exposure and exposure level after subcutaneous administration of uranium acetate (UA) (0.1-2 mg kg(-1) body weight). Although less of the injected uranium was deposited in the kidneys of the two younger rat groups, the proportion of the peak uranium content remaining in the kidneys after 2 weeks declined with age-at-exposure, suggesting reduced clearance in younger animals. In situ high-energy synchrotron radiation X-ray fluorescence analysis revealed site-specific accumulation of uranium in the S3 segment of the proximal tubules, distributed in the inner cortex and outer stripe of the outer medulla. Apoptosis and cell loss in the proximal tubules increased with age-at-exposure to 0.5 mg kg(-1) UA. Surprisingly, prepubertal rats were uniquely sensitive to uranium-induced lethality from the higher exposure levels. Observations of increased apoptosis in generating/re-generating tubules particularly in prepubertal rats could help to explain their high mortality rate. Together, our findings suggest that age-at-exposure and exposure level are important parameters for uranium toxicity; uranium tends to persist in developing kidneys after low-level exposures, although renal toxicity is more pronounced in adults.

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Rubidium Distribution in Kidneys of Immature Rats

Cited by 13 publications

References 16 publications

Evaluation of Thin Section Standards for Local Analysis of Light Elements by Micro-Pixe Analysis

Evaluation of Thin Section Standards for Local Analysis of Light Elements by Micro-Pixe Analysis

Phosphorus Localization and Its Involvement in the Formation of Concentrated Uranium in the Renal Proximal Tubules of Rats Exposed to Uranyl Acetate

Uranium dynamics and developmental sensitivity in rat kidney

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