Influence of heavy metals upon the retention and mobilization of polonium‐210 in rats
| Autor: | Holusa R, Curík R, G. Veselá, J. Rencová, A. Vlková |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Polonium
Erythrocytes Time Factors Metal ions in aqueous solution chemistry.chemical_element Urine Excretion Feces chemistry.chemical_compound Cations Metals Heavy Animals Tissue Distribution Radiology Nuclear Medicine and imaging Chelation Perchloric acid Rats Wistar Hydrogen peroxide Chelating Agents Radioisotopes Binding Sites Chromatography Radiological and Ultrasound Technology Radiochemistry Methylmercury Compounds Immunohistochemistry Rats Lead chemistry Female Metallothionein Digestion Cadmium |
| Zdroj: | International Journal of Radiation Biology. 80:769-776 |
| ISSN: | 1362-3095 0955-3002 |
| DOI: | 10.1080/09553000400017911 |
| Popis: | To provide information about the tissue retention and mobilization of the alpha-emitting radionuclide, polonium-210 (210Po), in rats under combined exposure to heavy metal ions and the chelating agent, 2, 3-dimercaptopropane-1-sulfonate (DMPS).Rats were pre-exposed intraperitoneally to either CdCl2 or Pb(CH3COO)2. 9 or 15 h later they received 210Po nitrate intravenously. The retention and excretion of 210Po via the urine and faeces of pre-exposed rats, as well as in pre-exposed rats treated with DMPS, were followed. The radioactivity due to 210Po in a broad spectrum of body tissues and excreta was measured by the liquid scintillation counting after sample digestion in a mixture of perchloric acid and hydrogen peroxide. The immunohistochemical localization of metallothioneins (MT) was studied using a mixture of murine monoclonal antibodies directed against MT I+II.The present study revealed different tissue distributions of polonium-210 in the rats pre-exposed to lead or cadmium ions when compared with that in 210Po only controls. Under combined exposure to Pb or Cd, the spontaneous excretion of 210Po was enhanced and could be further enhanced by treatment with DMPS. Treatment with this chelator was efficient even when its start was postponed until 24h after internal contamination of the body with 210Po.Polonium-210 is bound in vivo to binding sites on various biomolecules, among them erythrocytic enzymes and MT. This phenomenon explains the different affinity and overall distribution of 210Po in control body tissues. When the appropriate binding sites are occupied by lead or cadmium, enhanced natural excretion of polonium-210 occurs. |
| Databáze: | OpenAIRE |
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