Abstract:

[Abstract] Objective  To investigate the effect of hypoxic preconditioning (HPC) on middle cerebral artery occlusion (MCAO)-induced brain injury in mice，and changes of calcium/calmodulin-dependent protein kinaseⅡ(CaMKⅡ) phosphorylation thereof. Methods  Thirty-six healthy male BALB/c mice were randomly divided into 4 groups: the normoxic sham surgery (H0-sham) group, HPC-sham group, H0-ischemia group and HPC-ischemia group. Changes of CaMKⅡ phosphorylation in the brain of mice were detected by Western blot combined with Gel Doc imagine systems. Levels of CaMK Ⅱ phosphorylation in brain cortex of mice were detected by immunohistochemistry. Results  Both phosphorylation and protein expression levels in the ischemic core and penumbra were significantly decreased in H0-ischemia group compared with those in H0-sham group (P < 0.05). But the phosphorylation levels of CaMKⅡ and the positive cell number of p - CaMK Ⅱin the penumbra were significantly higher in HPC-ischemia group than those of H0-ischemia group (P < 0.05). Conclusion  The de? creased CaMKⅡ phosphorylation level in ischemia penumbra might involve in the attenuation of middle cerebral artery occlusion (MCAO)-induced brain injury in mice.

Key words: Cerebral hypoxic preconditioning, MCAO, CaMKⅡ, Phosphorylation, Protein expression