右美托咪定对肺癌根治术术侧肺组织自噬相关蛋白LC3的影响

Effects of Dexmedetomidine on the Expression of Autophagy Protein LC3 in Operated Lung Tissues of Patients Undergoing Radical Operation for Lung Cancer

关键词:  右美托咪定  呼吸  人工  肺  自噬

Key words:  dexmedetomidine  respiration  artificial  lung  autophagy

摘要:

目的 探讨右美托咪定对肺癌根治术单肺通气患者术侧肺组织自噬相关蛋白LC3的影响。方法 择期行肺癌根治术患者46例（美国麻醉医师协会分级Ⅰ~Ⅱ级），采用随机数字表法分为对照组和实验组各23例。实验组于麻醉诱导前静脉输注负荷量右美托咪定1.0 μg·kg^-1，用时15 min，然后以0.5 μg·kg^-1·h^-1的速度维持至手术结束前30 min；对照组静脉输注等容量生理盐水。于单肺通气即刻（T₁），单肺通气30 min（T₂）、60 min（T₃），术毕（T₄）时分别采集动脉血，进行动脉血气分析，计算氧合指数。采用ELISA法检测血浆TNF-α和IL-6浓度。切取拟切除肺肿瘤周边正常组织，采用Western blot法检测自噬标志蛋白LC3表达水平，计算LC3-Ⅱ/LC3-Ⅰ比值。结果 与对照组比较，实验组血浆TNF-α、IL-6的浓度降低，LC3-Ⅱ/LC3-Ⅰ比值和氧合指数升高（P<0.05）。2组患者单肺通气时间、出血量以及术后双腔支气管插管带管时间无明显差异。结论 右美托咪定可以增强肺癌根治术患者单肺通气期间术侧肺组织的自噬，减轻全身炎症反应，改善肺功能。

Abstract:

OBJECTIVE To evaluate the effect of dexmedetomidine on autophagy protein LC3 in operated lung tissues during one lung ventilation in patients undergoing radical operation for lung cancer. METHODS Forty-six patients scheduled for elective radical operation for lung cancer (ASA physical status Ⅰ-Ⅱ), were randomly divided into control group and experimental group. Each group included 23 patients. Before induction of anesthesia, dexmedetomidine was infused at a rate of 1.0 μg·kg^-1over 15 min, followed by continuous infusion at a rate of 0.5 μg·kg^-1·h^-1 until 30 min before the end of operation in experimental group; meanwhile the equal volume of normal saline was given in control group. At four time points, including immediately after one-lung ventilation(T₁), at 30 min(T₂) and 60 min(T₃)of one-lung ventilation, and at the end of operation(T₄), arterial blood samples were collected for blood gas analysis and oxygenation indices were calculated. Plasma concentrations of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) were measured by ELISA method. The specimens for normal lung tissues around the cancer were collected to measure the level of LC3 protein expression by Western blot and the ratio of LC3-Ⅱ/LC3-Ⅰwas calculated. RESULTS Compared with control group, plasma concentrations of TNF-α and IL-6 were significantly decreased, the ratios of LC3-Ⅱ/LC3-Ⅰand oxygenation indices were significantly increased (P<0.05) in experimental group. Moreover, there were no statistical difference in the time of one lung ventilation, blood loss and the time of tracheal tube extubation between two groups. CONCLUSION Dexmedetomidine can enhance autophagy in the operated lung tissues and mitigate inflammatory responses, improving pulmonary function during one lung ventilation in patients undergoing radical operation for lung cancer.