Intracellular Ca2+ concentration change of T24 cell under irradiation in the presence of TiO2 ultrafine particles

Hideki Sakai, Etsuro Ito, Ru Xiong Cai, Toru Yoshioka, Yoshinobu Kubota, Kazuhito Hashimoto, Akira Fujishima

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    102 Citations (Scopus)

    Abstract

    We respond that malignant cells are inactivated by photo-excited TiO2 particles (Cai, R.-X., et al. (1992) Cancer Res. 52, 2346-2348). In the present study, the process of cell death of a human bladder cell line T24 with the irradiated TiO2 was investigated by monitoring the time course change in intracellular calcium concentration ([Ca2+]i) under UV irradiation using calcium fluorescence indicator, fura-2. In the presence of photo-excited TiO2 particles (100 μg/ml), [Ca2+]i showed a rapid two-step increase, while in the absence of TiO2, it exhibited only a slight and monotonous increase or maintained a constant level. The rapid elevation of [Ca2+]i in the presence of photo-excited TiO2 particles was caused by the influx of extracellular Ca2+ through the plasma membrane and cell death occurred only after the second rapid elevation of [Ca2+]i. These results suggested that the cell membrane permeability to Ca2+ was promoted prior to cell death.

    Original languageEnglish
    Pages (from-to)259-265
    Number of pages7
    JournalBBA - General Subjects
    Volume1201
    Issue number2
    DOIs
    Publication statusPublished - 1994 Nov 11

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    Keywords

    • Fura-2
    • Intracellular Ca concentration
    • Photo-dynamic therapy
    • T24 cell
    • TiO
    • UV light

    ASJC Scopus subject areas

    • Biochemistry
    • Biophysics
    • Molecular Biology

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