右美托咪定对老龄大鼠反复七氟烷麻醉致神经认知障碍的抑制作用及可能机制

Inhibitory effect of dexmedetomidine on neurocognitive impairment induced by repeated sevoflurane anesthesia in aged rats and its possible mechanism

目的探究右美托咪定对老龄大鼠反复七氟烷麻醉致神经认知障碍的抑制作用及可能机制。方法30只SD大鼠随机分成对照组、七氟烷组及右美托咪定组,每组10只。水迷宫实验检测大鼠认知能力变化;HE染色观察海马组织形态学变化;TUNEL法检测海马组织神经元细胞凋亡;ELISA法检测海马组织炎症因子及脑损伤因子水平;免疫荧光检测海马组织MAP-2蛋白表达;Western blot检测α7nAChR和HDAC6蛋白表达。结果右美托咪定改善反复七氟烷麻醉老龄大鼠认知能力,改善大鼠海马组织形态,降低海马组织神经元细胞凋亡、炎症因子和脑损伤因子水平,增加α7nAChR蛋白表达水平,降低HDAC6蛋白表达水平。结论右美托咪啶减轻老龄大鼠反复七氟烷麻醉致神经认知障碍,其作用机制可能与α7nAChR-HDAC6通路有关。

Objective To explore the inhibitory effect of dexmedetomidine on neurocognitive impairment induced by repeated sevoflurane anesthesia in aged rats and its possible mechanism.Methods Thirty SD rats were randomly divided into control group,sevoflurane group and dexmedetomidine group,with 10 rats in each group.Water maze test was used to detect the change of cognitive ability of rats.Hippocampal histomorphology was observed by HE staining.TUNEL assay was used to detect neuronal apoptosis in hippocampus.The levels of inflammatory factors and brain injury factors in hippocampus were detected by ELISA.Immunofluorescence was used to detect expression of MAP-2 in hippocampus.The expressions ofα7nAChR and HDAC6 were detected by Western blot.Results Dexmedetomidine increased the cognitive ability of aged rats under repeated sevoflurane anesthesia,improved the morphology of hippocampal tissues,decreased the levels of neuronal apoptosis,inflammatory factors and brain injury factors,increased the expression ofα7nAChR protein,and decreased the expression of HDAC6 in hippocampal tissues.Conclusion Dexmedetomidine alleviates neurocognitive impairment induced by repeated sevoflurane anesthesia in aged rats,and its mechanism may be related to theα7NACR-HDAC6 pathway.