Taurine antagonizes calcium overload induced by glutamate or chemical hypoxia in cultured rat hippocampal neurons.

Taurine has been proposed to have antiexcitotoxic and antihypoxic activity. To explore the effect of taurine on neuronal calcium overload evoked by glutamate or hypoxia, we employed fluo-3 imaging of intracellular calcium ([Ca2+]i) in confocal laser scanning microscope to measure real-time changes of [Ca2+]i arose from glutamate/2,4-dinitrophenol (DNP, mimic hypoxia) and taurine in cultured rat hippocampal neurons. We found that 3 mM taurine could inhibit [Ca2+]i elevation ascribed to 0.5 mM glutamate or 0.2 mM DNP. Low (0.5 mM) or high (12 mM) level of taurine displayed no significantly depressant effect. However, sole application of taurine could increase [Ca2+]i transiently. The results indicate that taurine in moderate concentration may exert antiexcitotoxic and antihypoxic effect partially via its antagonism to [Ca2+]i overload.