Influence of the carcinogenic oestrogen diethylstilboestrol on the intracellular calcium level in C6 rat glioma cells.
The synthetic oestrogen diethylstilboestrol (DES) causes a dose-dependent elevation of the cytoplasmic Ca(2+) concentration in C6 rat glioma cells. This Ca(2+) rise is caused neither by Ca(2+) influx nor by release from the Ca(2+) stores of the endoplasmic reticulum. Therefore it seems likely that DES mobilizes Ca(2+) from a mitochondrial source. The DES-induced Ca(2+) signal is remarkably similar to the one induced by the tumour promotor thapsigargin. As this compound causes leakage of calcium from the endoplasmic reticulum it seems possible that DES induces a similar leakage from mitochondrial Ca(2+) stores. It remains to be established whether the DES-mediated rise in intracellular calcium is causally related to the tumour-promoting properties of this compound.
Tas
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Institute of Toxicology, University of Würzburg, D-8700 Würzburg, Germany.
Stopper
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Koschel
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Schiffmann
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