Effect of isoflurane post-conditioning on hippocampus neurons with cerebral ischemic reperfusion injury in rats / 临床麻醉学杂志

ABSTRACT

Objective To investigate whether Wnt/β-catenin signaling pathway mediating the neuroprotection of isoflurane post-conditioning in hippocampal neurons damage induced by ischemia/reperfusion injury in rats.Methods According to the randomized principle, 60 male Sprague-Dawley rats were randomly divided into five groups (12 rats in each group)sham group (group S), model group (group M), ISO+model group (group MI), ISO+model+DKK-1 group (group MDI) and model+DKK-1 group (group MD).A rat model of middle cerebral artery occlusion (MCAO) was established with 90 min ischemia followed by 24 hreperfusion.Group S was only exposed to one side of the internal carotid artery without fishing line.Isoflurane post-conditioning groups (group MI, MDI) were immediately treated with 1.5％isoflurane for 60 min at the onset of reperfusion.DKK-1 (5μg/kg) was injected intracerebroventricularly 30 min before the model established in group MDI and group MD.After reperfusion for 24 h, Longa score method was used for neurological deficit score.HE staining and Tunel fluorescence was employed to observe the morphological changes of neurons.Immunohistochemistry and Western Blot were applied to detect the expression of target protein in CA1 region.Results Compared with group S, the neurobehavioral score, the number of apoptosis and the expression of Bax and GSK-3βprotein in group M all increased (P<0.05), while the expression ofβ-catenin and Bcl-2/Bax ratio decreased (P<0.05) ;Compared with group M, the neurobehavioral score, the number of apoptosis and the expression of Bax protein were significantly decreased (P<0.05), while the expression of Bcl-2, β-catenin protein and the Bcl-2/Bax ratio were significantly increased (P<0.05) in group MI.Compared with group MI, the neurobehavioral score, the number of apoptosis, Bax and GSK-3βprotein in group MDI were significantly increased (P<0.05), while the Bcl-2, β-catenin protein expression, and Bcl-2/Bax ratio were significantly decreased (P<0.05).Conclusion Isoflurane post-conditioning may protect the hippocampus neurons against cerebral ischemic reperfusion-induced damage via the way that the Wnt/β-catenin signaling pathway regulates the expression levels of Bcl-2 and Bax proteins in rats.