Objective To explore the optimal reaction time of thrombin combined with hypoxia on PC12 cell injury ,and to provide experimental method for the study of the significance of thrombin in ischemic brain injury .Methods the PC12 cell injury model induced by hypoxia in vitro was established .In the conventional cell culture method ,three 1% O2 (5% CO2 ,6 h ,94% N2 ) and DMEM (24 h) cells were used to simulate ischemia ,and four (50 ,150 and 200 U/ml) were added to the different concentrations of thrombin (0 ,100 ,and 12 h) .Cell survival ra...