2007 Volume 24 Pages 129-132
In the previous study, we found that the exposure of tributyltin chloride (TBTC) made to disturb the balance of trace elements in brain tissues remarkably and to accumulate excessive calcium in olfactory bulb and olfactory epithelium1-5). Moreover, under the conditions, pathological cell death of neuron, especially granular neuron, was observed in olfactory bulb and olfactory epithelium1-5). Therefore, we have predicted that organotin-induced cell death of the olfactory neurons may be caused by the accumulation of excessive calcium. However, a mechanism on the cell death by the higher level concentration of calcium and the location of intracellular calcium have not been clear.
In this study, the olfactory neurons were isolated from olfactory bulb and the movement and location of intracellular calcium in the olfactory neurons after the exposure of TBTC were investigated by an in vitro experimental system. The movement and location of calcium in the olfactory neurons after the exposure of TBTC or the higher level concentration of calcium were observed by a confocal laser scanning microscopic system. As the results, transference of cytosolic calcium to nucleus in neurons after organotin-exposure was observed in the fluorescent images. This result suggests the transference of excessive calcium to the nucleus is strongly associated with the activation of endonuclease, DNase I in the nucleus, followed by the induction of apoptosis.
