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水通道蛋白4缺失对静脉麻醉药催眠效应的影响

周巧梅, 吕云落, 胡刚, 曾因明, 屠伟峰

广州军区广州总医院麻醉科，广州 510010；南京医科大学附属南京第一人民医院麻醉科，南京 210006；南京医科大学神经药理学实验室，南京210029；徐州医学院江苏省麻醉学重点实验室，徐州 221002

摘要

水通道蛋白4 (aquaporin-4, APQ4)参与调节突触神经递质释放，而全麻状态的形成主要由神经元兴奋性及神经元之间突触传递功能改变所引起的。本文旨在研究AQP4与全麻药物作用的相关性，探讨AQP4是否参与调节全麻药物效应的发挥及其可能机制。实验对象是成年雄性AQP4基因敲除(KO)小鼠与野生型CD1 (WT)小鼠。采用行为学催眠实验，分别给予WT/KO小鼠三种作用机制不同的静脉麻醉药(丙泊酚、氯胺酮和戊巴比妥钠)，观察记录小鼠翻正反射消失时间和恢复时间；进行微透析递质测定，WT/KO小鼠立体定位前额皮质，收集丙泊酚腹腔注射前、后该部位透析液，高效液相色谱法(HPLC)检测透析液内氨基酸类递质浓度。结果显示，相对于WT小鼠，氯胺酮组和戊巴比妥钠组KO小鼠翻正反射消失时间提前，而持续时间延迟；而丙泊酚组KO小鼠翻正反射持续时间则明显缩短。前额皮质氨基酸类神经递质在给予丙泊酚后的不同时段均表现为较基础水平增加，给药后KO小鼠前额皮质天冬氨酸、谷氨酸和γ-氨基丁酸(GABA)的升高模式与WT小鼠有显著的差异。值得注意的是，在这两种基因型的小鼠前额皮质中GABA升高持续时间与药物诱导的翻正反射消失持续时间有相关关系。本研究证实AQP4基因缺失影响静脉全麻药催眠效应的发挥；丙泊酚麻醉效应与其诱导的前额皮质神经递质释放相关，提示AQP4基因敲除影响脑内神经递质在麻醉状态时的释放可能是其造成麻醉药物效应改变的原因之一。

关键词： 水通道蛋白4; 丙泊酚; 翻正反射; 神经递质; 微透析

分类号：R338

Effect of aquaporin-4 deficiency on intravenous anaesthetic induced hypnotic effects in mice

ZHOU Qiao-Me, LV Yun-Luo, HU Gang, ZENG Yin-Ming, TU Wei-Feng

Department of Anaesthesiology, General Hospital of Guangzhou Military Command of PLA, Guangzhou 510010, China； Department of Anaesthesiology, Affiliated Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China； Laboratory of Neuropharmacology, Nanjing Medical University, Nanjing 210029, China； Jiangsu Province Key Laboratory of Anaesthesiology, Xuzhou Medical College, Xuzhou 221002, China.

Abstract

The deficiency of aquaporin-4 (AQP4) has been reported to alter release of neurotransmitters in the mouse brain. However, the functional relevance of AQP4 in mediating essential components of the general anaesthetic state is unknown. The aim of the present study was to investigate the role of AQP4 in general anaesthesia in mice lacking AQP4. The hypnotic effects of propofol, ketamine, and pentobarbital in AQP4 knockout (KO) and CD1 control mice were evaluated using the behavioural endpoint of loss of righting reflex (LORR). The effects of propofol on extracellular levels of amino acids in prefrontal cortex of freely moving mice were investigated using microdialysis coupled to high performance liquid chromatography with fluorescent detection. The result showed that, after receiving ketamine or pentobarbital, LORR occurred at earlier time in KO mice than that in control animals. Intraperitoneal injection of ketamine or pentobarbital increased the duration of LORR. After the administration of propofol, the duration of LORR was significantly reduced in KO mice compared with that in controls. Propofol increased the extracellular levels of aspartate, glutamate, and GABA, but not taurine, in prefrontal cortex. There were significant differences of increase patterns of the three kinds of neurotransmitters between KO and WT mice. Notably, the duration of GABA level increase correlated with the duration of LORR in two genotypes of mice. These results provide in vivo evidence of different responses in time-dependent release of excitatory and inhibitory neurotransmitters in prefrontal cortex of the two genotypes of mice. It is suggested that changes in anaesthetic reactions in mice with AQP4 loss may be related to neurotransmitter regulation, and that normal functioning of AQP4 plays an important role in the maintenance of anaesthetic hypnosis.

Key words: aquaporin-4; propofol; righting reflex; neurotransmitters; microdialysis

收稿日期：2013-06-26　　录用日期：2013-09-27

通讯作者：曾因明,屠伟峰　　E-mail: zym_xzmc@163.com, wftuyx02@163.com

引用本文：

周巧梅, 吕云落, 胡刚, 曾因明, 屠伟峰. 水通道蛋白4缺失对静脉麻醉药催眠效应的影响[J]. 生理学报 2013; 65 (6): 569-576.

ZHOU Qiao-Me, LV Yun-Luo, HU Gang, ZENG Yin-Ming, TU Wei-Feng. Effect of aquaporin-4 deficiency on intravenous anaesthetic induced hypnotic effects in mice. Acta Physiol Sin 2013; 65 (6): 569-576 (in Chinese with English abstract).