Abstract: Objective To explore initially the role of extracellular signal-regulated kinase (ERK1/2) in cerebral ischemic preconditioning. Methods Healthy adult SD rats were randomly divided into 5 groups: normal control group; sham group; ischemic preconditioning or ischemia tolerance group; bee venom group; peripheral noxious tolerance group. SDS-PAGE, Western blot and Gel Doc imagine systems were applied to determine the ERK1/2 phosphorylation and protein expression in somatosensory cortex and hippocampus of rats. Results The phosphorylation level of ERK1 in somatosensory cortex increased significantly (P<0.05) after ischemic preconditioning, while no significant changes in ERK2 and that of ERK1/2 in hippocampus. No significant changes in ERK1/2 protein expression were found both in somatosensory cortex and hippocampus after ischemic preconditioning. Conclusion The increased ERK1 phosphorylation level in somatosensory cortex may be involved in cerebral ischemic preconditioning.

Key words: cerebral ischemic preconditioning, extracellular signal-regulated kinase (ERK1/2), phosphorylation, protein expression