Postconditioning with sevoflurane ameliorates spatial learning and memory deficit after hemorrhage shock and resuscitation in rats.

Background: Severe hemorrhage shock and resuscitation are a systemic ischemia-reperfusion phenomenon which can induce learning and memory deficit in human and rats. Sevoflurane postconditioning has been proved to offer neuroprotection under different setting of cerebral ischemia-reperfusion in rats. The aim of this study was to investigate whether sevoflurane postconditioning could improve spatial learning and memory ability after hemorrhage shock and resuscitation in rats.

Methods: Thirty-five male rats were randomized into five groups: sham group, shock group, low concentration (sevo1, 1.2%), middle concentration (sevo2, 2.4%), and high concentration (sevo3, 3.6%) of sevoflurane postconditioning groups. The spatial learning and memory ability of rats were measured by Morris water maze 3 d after the operation. The expression of choline acetyltransferase (CHAT) and acetylcholinesterase (ACHE) in the hippocampus CA1 region was observed by immunohistochemistry method after the Morris water maze test.

Results: The ability of spatial learning and memory of rats and the expression of CHAT was significantly declined, while the expression of ACHE increased in the shock group compared with the sham group (P < 0.05). Sevoflurane postconditioning with the concentrations of 2.4% and 3.6% significantly ameliorated the spatial learning and memory ability and increased the expression of CHAT and decreased the expression of ACHE in hippocampal CA1 region when compared with shock group (P < 0.05).

Conclusions: Postconditioning with sevoflurane at the concentrations of 2.4% and 3.6% which improved the ability of spatial learning and memory after hemorrhage shock and resuscitation in rats may involve the protection of the cholinergic neurons in hippocampal CA1 region.