Objective    To investigate the effects of inflammatory chemokine LPS and/or IFN-γ on astrocytes.     Methods    After LPS and IFN-γ applied to the purified cultured mouse astrocytes

TNF-α and nitric oxide (NO) secreted from astrocytes and intracellular calcium concentration ([Ca

2+

]

i) were detected by ELISA

Griess and confocal laser scanning microscopy

respectively.     Results    Treatment with LPS (500 ng/ml) or IFN-γ (100 U/ml) for 24 h significantly increased the concentration of TNF-α and NO. Coadministration of LPS and IFN-γ showed a synergistic effect on the astrocytes. By using Ca

2+

imaging

we found

that [Ca

2+

]

i signal was significantly increased after LPS and/or IFN-γ treatment for 24 h. Also

acute treatment with LPS or IFN-γ could evoke Ca

2+

oscillations. In contrast

after application of these stimuli over 24 h

the Ca

2+

signal was increased more slowly.     Conclusion    Application of LPS and/or IFN-γ evoked TNF-α and NO secretion and [Ca

2+

]

i elevation in cultured astrocytes

suggesting that astrocytes could be activated by LPS and IFN-γ.