右美托咪定对术后老龄小鼠海马组织白介素1β和肿瘤坏死因子α表达的影响
Effects of dexmedetomidine on expressions of IL-1β and TNF-α in hippocampus tissues of aged mice after surgery

目的 探讨右美托咪定对手术创伤后老龄小鼠海马组织白介素1β （IL-1β）和肿瘤坏死因子α （TNF-α）表达以及术后认知功能障碍(POCD)的影响。方法 将105只老龄昆明小鼠随机分为4组。空白对照组（n=15)：不实施麻醉和手术；麻醉药物组（n=30)：腹腔注射氯胺酮100 mg/kg，持续吸入异氟醚60 min；麻醉药物+手术组（n=30)：给予复合麻醉药物后实施剖腹探查脾切除手术；右美托咪定干预组（n=30）：术前30 min各取15只小鼠分别给予右美托咪定15、25 μg/kg腹腔内注射。术后第1日、第3日行Y迷宫实验(右美托咪定干预组在术后第3日进行)，记录各组所需的训练次数；荧光定量PCR 和Western blotting检测海马组织IL-1β、TNF-α mRNA及蛋白的表达。结果 与空白对照组比较，麻醉药物组术后第1日训练次数增多（P<0.05），术后第3日恢复正常（P>0.05），麻醉药物+手术组术后第1日、第3日训练次数增多（P<0.01，P<0.05）；术后第3日，右美托咪定15、25 μg/kg干预组与空白对照组比较，差异均无统计学意义（P>0.05）。与空白对照组比较，麻醉药物+手术组术后第1日、第3日IL-1β、TNF-α mRNA及蛋白的表达量均显著升高（P<0.05或P<0.01）；麻醉药物组术后第1日、第3日及右美托咪定干预组术后第3日IL-1β、TNF-α mRNA及蛋白的表达量与空白对照组比较，差异无统计学意义（P>0.05）。结论 右美托咪定预处理能降低小鼠海马组织IL-1β、TNF-α mRNA及蛋白的表达，其改善小鼠POCD的作用与抑制海马炎症反应有关。
： Objective To explore the effects of dexmedetomidine on expressions of IL-1 β and TNF-α in hippocampus tissues of aged mice after surgery and postoperative cognitive decline (POCD). Methods A total of 105 aged Kunming mice were randomly divided into 4 groups, i.e. control group (n=15) that received no anesthesia and surgery, anesthesia group (n=30) that received consecutive isoflurane inhalation for 60 min and intraperitoneal injection of ketamine of 100 mg/kg, splenectomized group (n=30) that underwent splenectomy after anesthesia, intervention group (n=30) that received intraperitoneal injection of dexmedetomidine of 15 and 25 μg/kg (15 mice for each dose) 30 min before anesthesia and surgery. Y-maze experiments were conducted 1 d and 3 d after surgery (Y-maze experiments were conducted 3 d after surgery for the intervention group). The trial numbers of each group were recorded. The mRNA and protein expressions of IL-1β and TNF-α in hippocampus tissues were detected by the qRT-PCR and Western blotting. Results The trial number of the anesthesia group was more than that of the control group 1 d after surgery (P<0.05) and was back to normal 3 d after surgery (P>0.05). The trial number of the splenectomized group was more than that of the control group 1 d and 3 d after surgery (P<0.01, P<0.05). The differences of the intervention group and control group 3 d after surgery were not statistically significant (P＞0.05). Compared with the control group, the mRNA and protein expressions of IL-1β and TNF-α of the splenectomized group significantly increased 1 d and 3 d after surgery (P<0.05 or P<0.01), and the differences of the mRNA and protein expressions of IL-1β and TNF-α of the anesthesia group (1 d and 3 d after surgery), intervention group (3 d after surgery), and control group were not statistically