Effect of emulsified isoflurane preconditioning on postsynaptic density protein 95 activation in brain during focal cerebral ischemia-reperfusion injury in rats

Objective To investigate the effect of emulsified isoflurane preconditioning on postsynaptic density protein 95 (PSD95) activation in brain during focal cerebral ischemia-reperfusion (I/R)injury in rats.Methods Thirty-two pathogen-free male SD rats weighing 280-300 g were randomly divided into 4 groups (n =8each): sham operation group(group S),group I/R,emulsified isoflurane group(group EI) and lipid emulsion group(group LE).Focal cerebral I/R was induced by middle cerebral artery occlusion for 2 h followed by reperfusion.8％ emulsified isoflurane 10.5 ml/mg or 30％ lipid emulsion 10.5 ml/mg was injected intraperitoneally at 24h before I/R in groups EI and LE respectively.The neurologic deficit score (NDS) was evaluated at 6 h of reperfusion and then 4 rats were sacrificed,and brains were removed for determination of phosphorylatied PSD95 (pPSD95) expression in ischemia cortex and hippocampus by Western blot.Four rats were sacrificed at 24 h of reperfusion and then their brains were removed for determination of infarct volume percentage.Results NDS,infarct volume percentage and pPSD95 expression in ischemia cortex and hippocampus were higher in groups I/R,EI and LE than in group S( P ＜ 0.01 ).NDS,infarct volume percentage and pPSD95 expression in ischemia cortex and hippocampus were lower in group EI than in group I/R( P ＜ 0.05).There was no significant difference in NDS,infarct volume percentage and pPSD95 expression between groups I/R and LE(P ＞ 0.05).Conclusion Emulsified isoflurane preconditioning can attenuate focal cerebral I/R injury in rats by inhibiting PSD95 activation in brain. Key words: Isoflurane ;  Fat emulsions, intravenous ;  Membrane proteins;  Reperfusion injury ;  Brain;  Ischemic preconditioning