| Autor: |
Oyama, Yasuo1 oyama@ias.tokushima-u.ac.jp, Arata, Tomohiro1, Chikahisa, Lumi2, Umebayashi, Chisato1, Tabaru, Ken1, Sakai, Kei1, Hayashi, Hiromi1 |
| Předmět: |
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| Zdroj: |
Environmental Toxicology & Pharmacology. Jan2003, Vol. 13 Issue 1, p29. 8p. |
| Abstrakt: |
As tri-n-butyltin (TBT), one of the environmental pollutants, is accumulated in wild animals, concern regarding the toxicity of TBT in both wildlife and human is increasing. TBT has been reported to increase intracellular Ca2+ concentration in several types of cells. In order to examine how Ca2+ is involved in TBT-induced cell death, the effect of TBT on rat thymocytes has been compared with that of A23187, a calcium ionophore, under various concentrations of external Ca2+ using a flow cytometer and fluorescent probes. Although both TBT and A23187 were toxic to cells under normal Ca2+ condition, under external Ca2+-free condition the cytotoxic action of TBT was potentiated without changing the threshold concentration while that of A23187 was completely abolished. A23187 attenuated the TBT-induced descent in cell viability under normal Ca2+ concentration despite intracellular Ca2+ concentration was increased. As external Ca2+ concentration increased, the TBT-induced increase in number of dead cells gradually decreased whereas the number of cells in an early stage of apoptosis increased. Results suggest that Ca2+ has contradictory actions on the process of TBT-induced cell death in rat thymocytes. [Copyright &y& Elsevier] |
| Databáze: |
GreenFILE |
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