镇静、麻醉剂量异丙酚在大鼠不同脑区分布的研究

Because of its characteristic fast onset, short duration of action and rapid recovery with a low incidence of post-operative side effects, propofol becomes a very popular intravenous general anesthetic in modern society. Although propofol is known to mediate the activity of the GABA-A receptors, its detailed mode of action (MOA) and its specific macromolecular targets have not been fully deciphered. Previous experiments aiming at locating the action site of propofol in brain led to controversial results. Low accuracy of methods used for measuring the propofol concentration in brain and low reproducibility of these experiments were the main reasons responsible for the discrepancy. Propofol of small dose leads to sedation, while large dose results in anesthesia. And it is not known definitely that whether this two effects result from the same pharmacological mechanism and whether the drug’s distributions in brain of different doses are consistent. Based on the brain-uptake theory, we plan to use a stable isotope-labeled propofol to facilitate the determination of the propofol concentration in different brain regions and its distribution law by liquid chromatography-tandem mass spectrometry. These results would help us to better understand the MOA and pharmacology of propofol in rats. The outcome of this project should also offer some theoretical basis for further exploration of the mechanism of general anesthesia and for the prevention of anesthesia nervous complications.

异丙酚具有环境污染少、苏醒平稳等优点，是目前临床上静脉麻醉的代表药物之一，但其作用机制以及在机体内的确切作用靶点尚不完全明确。国内外有研究试图通过测定不同组织内异丙酚的浓度来定位作用靶点，但研究结果差异较大，测量方法精确度低、样本需求量大、可重复性低是其主要原因。小剂量异丙酚具有镇静作用，大剂量则具有麻醉作用，这两种药理作用的机制是否一致，在靶器官——大脑内的分布规律又如何，目前尚无明确结论。本研究以脑摄取理论为基础，通过同位素标记内标方法结合液相-串联质谱分析技术，探寻一种能更加精确测量给药后动物不同脑区异丙酚含量的方法，并阐明该药在镇静剂量及麻醉剂量下不同脑区的分布规律；而探索异丙酚的具体作用靶点和作用机制，能为进一步探索全麻机理及预防麻醉后神经系统并发症提供理论基础。

本研究以脑摄取理论为基础，通过实验，完成了氘代内标液相色谱-串联质谱法的标准曲线绘制、氘代内标液相色谱-串联质谱法的标准曲线质控、大鼠的镇静麻醉模型建立以及镇静、麻醉剂量异丙酚在大鼠的脑区分布的测定。验证了同位素标记内标方法结合液相-串联质谱分析技术对测定大脑不同脑区异丙酚含量的可行性，证明了同位素内标液相-串联质谱是测量给药后动物不同脑区异丙酚含量的精确方法，并阐明了该药在镇静剂量及麻醉剂量下不同脑区的分布规律，为进一步探索全麻机理及预防麻醉后神经系统并发症提供理论基础。