Estimation of increased concentration of intracellular Cd2+ by fluo-3 in rat thymocytes exposed to CdCl2

摘要: Cadmium, an environmental pollutant, has been reported to induce apoptosis in murine lymphocytes. To reveal the mechanism of cadmium-induced apoptosis, one important questions is whether cadmium increases intracellular concentration Ca2+ ([Ca2+]i), Cd2+ ([Cd2+]i) or both. It difficult detect increase [Ca2+]i using Ca2+-chelator-based fluorescent indicators presence because their sensitivity Cd2+. Therefore, study on membrane response such as Ca2+-dependent hyperpolarization gives a clue [Cd2+]i increased. Cadmium at concentrations 3 μM more dose-dependently augmented fluo-3 fluorescence rat thymocytes, presumably suggesting increased [Ca2+]i. However, membranes were not hyperpolarized although cells possess K+ channels. One may argue that inhibits channels so fails hyperpolarize membranes. unlikely by A23187, calcium ionophore, elicited Furthermore, profile cytotoxicity induced cadmium, examined ethidium bromide and annexin V-FITC, was different from A23187. Taken together, it concluded application rather than resulting induction cytotoxicity.