吸入不同浓度麻醉药对小鼠大脑核团的影响

赵萌萌; 杨丽; 蒋明; 梁昕悦; 施翔鹏; 方芳; 仓静

doi:10.12025/j.issn.1008-6358.2023.20231257

摘要:

目的分析不同浓度、不同种类吸入性麻醉药物对小鼠大脑核团中c-Fos表达的影响，探讨核团激活（或抑制）在吸入性麻醉药诱导的意识消失中的可能作用。

方法选择成年雄性C57BL/6小鼠30只，8周龄，体质量22~23 g。将小鼠随机分为5组：对照组（C组，吸入100%纯氧）、吸入0.8%异氟醚组（IL组）、吸入1.4%异氟醚组（IH组）、吸入1.3%七氟醚组（SL组）和吸入2.5%七氟醚组（SH组），每组6只。所有小鼠接受气体暴露2 h后立即进行心脏灌流和剥离取脑。采用免疫荧光染色检测小鼠全脑c-Fos表达情况，采用c-Fos和精氨酸加压素（arginine vasopressin, AVP）或c-Fos和催产素（oxytocin, OXT）共同免疫荧光染色检测小鼠视上核（supraoptic nucleus, SON）中AVP和OXT的表达情况。

结果 5组小鼠大脑核团中的SON、中央杏仁核（central amygdala, CeA）、终纹床核（bed nucleus of stria terminalis, BNST）、前背侧视前核（anterodorsal preoptic nucleus, ADP）、下丘脑外侧区（lateral hypothalamic area, LHA）、扣带回皮质（cingulate cortex, Cg）、次级运动皮质（secondary motor cortex, M2）的c-Fos表达数量差异有统计学意义。与C组相比，IL组、IH组、SL组和SH组SON、CeA和BNST中c-Fos阳性细胞显著增加（P＜0.05），而ADP和LHA中c-Fos阳性细胞显著减少（P＜0.05）；IH组和SH组Cg中c-Fos阳性细胞显著减少（P＜0.05）；IH组M2中c-Fos阳性细胞显著减少（P＜0.05）。与IL组、SL组相比，IH组和SH组SON中c-Fos阳性细胞明显增加（P＜0.05）。与C组相比，IL组、IH组、SL组和SH组SON脑区AVP神经元激活百分比显著升高（P＜0.000 1）。

结论吸入不同浓度异氟醚或七氟醚可增加小鼠大脑核团SON、CeA和BNST中c-Fos阳性细胞数量，减少小鼠大脑核团ADP、LHA、Cg和M2中c-Fos阳性细胞数量。SON脑区AVP神经元激活可能参与异氟醚或七氟醚诱导的意识消失。

Abstract:

Objective To analyze the effects of different concentrations and different types of inhaled anesthetics on the expression of c-Fos in mouse brain nuclei, and to explore the possible role of nuclear activation (or inhibition) in the loss of consciousness induced by inhaled anesthetics.

Methods A total of 30 male adult C57BL/6 mice, aged 8 weeks and weighing 22-23 g were selected. Mice were randomly divided into 5 groups: control group (group C, inhaled 100% pure oxygen), inhaled 0.8% isoflurane group (group IL), inhaled 1.4% isoflurane group (group IH), inhaled 1.3% sevoflurane group (group SL) and inhaled 2.5% sevoflurane group (group SH), 6 mice in each group. All mice were transcardially perfused immediately after the gas exposure for 2 hours. Immunofluorescence staining was used to detect the c-Fos expression in the whole brain of mice. C-fos and arginine vasopressin (AVP) or c-Fos and oxytocin (OXT) immunofluorescence staining were used to detect the expression of AVP and OXT in supraoptic nucleus (SON).

Results There were significant difference between 5 groups in c-Fos expression in SON, central amygdala (CeA), bed nucleus of striatum (BNST), anterodorsal preoptic nucleus (ADP), lateral hypothalamic area (LHA), cingulate cortex (Cg) and secondary motor cortex (M2). Compared with group C, the c-Fos positive cells in SON, CeA and BNST of group IL, group IH, group SL and group SH were significantly increased (P < 0.05), while c-Fos positive cells in ADP and LHA were significantly decreased (P < 0.05), c-Fos positive cells in Cg of group IH and group SH were significantly decreased (P < 0.05) and c-Fos positive cells in M2 of group IH were significantly decreased (P < 0.05). Compared with group IL and group SL, c-Fos positive cells in SON of group IH and group SH were significantly increased (P < 0.05). Compared with group C, the activation percentage of AVP neurons in SON brain region of group IL, group IH, group SL and group SH was significantly increased (P < 0.000 1).

Conclusions Inhaling different concentrations of isoflurane or sevoflurane can increase the number of c-Fos positive cells in SON, CeA and BNST, and reduce the number of c-Fos positive cells in ADP, LHA, Cg and M2 in mouse brain. The activation of AVP neurons in SON may be involved in the mechanism of loss of consciousness induced by isoflurane or sevoflurane.

吸入不同浓度麻醉药对小鼠大脑核团的影响

Effects of inhalation of general anesthetics at different concentrations on brain nuclei in mice