异丙酚对健康志愿者不同脑区神经递质水平的影响

Effects of propofol on metabolism of neurotransmitters in different regions of CNS in healthy volunteers

目的评价异丙酚对健康志愿者不同脑区神经递质水平的影响,探讨异丙酚的全麻机制。方法健康志愿者10名,应用磁共振波谱分析(1H-MRS)技术,分别在清醒状态下行MRS扫描, 作为自身对照波谱;然后靶控输注异丙酚,效应室浓度达3．0μg·ml-1时进行第二次MRS扫描,采集波谱。MRS扫描采用点解析波谱序列(PRESS)。扫描选择的感兴趣区(VOI)包括皮层运动区、皮层感觉区、丘脑、海马和基底节区。以各波谱峰下面积计算N-乙酰基天门冬氨酸(NAA)、谷氨酸(Glu)、γ-氨基丁酸(GABA)、胆碱类化合物(Cho)和肌酸(Cr)水平的变化。结果与清醒状态比较,异丙酚效应室浓度达3．0μg·ml-1时,丘脑和海马区NAA水平,丘脑、海马和基底节区Glu水平,皮层运动区、皮层感觉区、丘脑、海马和基底节区Cho水平降低(P<0．05);皮层运动区、皮层感觉区、丘脑、海马和基底节区GABA水平升高(P<0．05);Cr水平在上述5个区域差异无统计学意义(P>0．05)。丘脑和海马 GABA变化率大于其他部位(P<0．05或0．01)。结论异丙酚麻醉对健康志愿者不同脑区NAA、Glu、 GABA、Cho等神经递质水平均有影响,其中GABA可能在异丙酚的全麻机制中发挥较为重要作用。

Objective To investigate the changes in the metabolism of neurotransmitters in different regions of the brain induced by propofol in healthy volunteers using the proton magnetic resonance spectroscopy （MRS） technology.Methods IH-MRS was performed in ten 20-40 year old healthy volunteers. Each volunteer underwent MRS scan twice. The first MRS scan was performed when they were conscious as baseline control value. The second scan was performed during target-controlled infusion （TCI） of propofol. The target effect-site concentration was set at 3.0μg·ml^-1 . Volume of interest （VOI） included sensory cortex, motor cortex, thalamus, hippocampas and basal ganglia. The metabolites in the spectra included N-acetyl-aspartic acid （NAA）, glutamic acid （Glu）, GABA, choline compounds （Cho） and creatine （Cr）. Results During TCI of propofol MAP and RR were significantly decreased （ P 〈 0.05 ）, while HR and SpO2 remained relatively unchanged （ P 〉 0.05 ） as compared to the baseline value when the volunteers were conscious. During TCI of propofol the NAA content in thalamus and hippecampus, Glu content in thalamus, hippocampus and basal ganglia and Cho content in all the 5 regions of the brain were significantly decreased （P 〈 0.05） whereas the GABA content in the 5 regions was significantly increased （ P 〈 0.05） as compared to the baseline values. The changes in GABA content in thalamus and hippocampus were relatively bigger than those in the other 3 brain regions. There was no significant change in Cr content in the 5 regions during TCI of propofol. Conclusion Propofol anesthesia has significant effects on NAA, Glu, GABA and Cho contents in the different brain regions, especially GABA which may play an important role in the mechanism of propofol anesthesia.