大黄素对辣椒素诱导的TRPV1通道电流的抑制作用  

Emodin Inhibits Capsaicin-Induced TRPV1 Current

作　　者：胡益[1,2,3] 张迪[1,2,3] Wolfgang Schwarz HU Yi ZHANG Di Wolfgang Schwarz(Department of Aeronautics and Astronautics, Fudan University, Shanghai 200433, China Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, Shanghai 200433, China Shanghai Research Center of Acupuncture and Meridians, Shanghai 201203, China Institute for Biophysics, J. W. Goethe University, Frankfurt am Main 60438 ,Germany)

机构地区：[1]复旦大学航空航天系,上海200433 [2]上海市针灸机制与穴位功能重点实验室,上海200433 [3]上海市针灸经络研究中心,上海201203 [4]法兰克福大学生物物理学系,法兰克福60438

出　　处：《复旦学报（自然科学版）》2017年第3期366-373,共8页Journal of Fudan University：Natural Science

基　　金：国家自然科学基金(81590950;81102630);国家重点基础研究发展规划(2012CB518502);上海市针灸机制与穴位功能重点实验室资助(14DZ2260500)

摘　　要：本研究通过显微注射技术将TRPV1 cRNA(1ng/nL)注射至非洲爪蟾卵母细胞(20nL/个)体内,放置于G-ORi培养液中,并在(19±1)℃的恒温培养箱内表达.同时利用灌流技术将不同浓度梯度的大黄素、辣椒素按照设计顺序依次灌流进入流动腔,同时控制流速保证非洲爪蟾卵母细胞完全浸没于流动腔内.使用双电极电压钳技术记录0.1,1.0,10.0,50.0μmol/L浓度梯度的大黄素对500nmol/L浓度的辣椒素激活TRPV1电流的影响.得到大黄素作用辣椒素激活TRPV1通道的抑制作用表现出浓度依耐性和电压非依赖性,IC50=38μmol/L,Hill系数n=0.5.结果表明了大黄素对TRPV1位点的相互作用是负协同的,在天然药物里面是一类比较弱的拮抗剂,且大黄素在ORi溶液中开始析出沉淀的浓度在50~60μmol/L之间.我们首次发现了大黄素能够抑制TRPV1通道电流,这可能为开发新的镇痛药物提供理论基础.Xenopus laevis oocytes were selected and injected with 20 ng cRNA（at 1 ng/nL）before the experiments,uninjected oocytes served as controls.The cells were stored at （19±1）℃ in G-ORi solution for incubation.Different gradient concentrations of emodin were perfused into chamber as arranged order in turns.Xenopus laevis oocytes should be fully immersed in solutions under control of flow speed.Two-electrode voltage clamp was used to record the TRPV1 current activated by gradient concentrations of emodin.Inhibitory effects of 0.1,1.0,10.0,50.0μmol/L emodin on 500 nmol/L capsaicin-induced TRPV1 currents have shown characters of concentration dependency and voltage independency as well,IC_（50）=38 μmol/L and Hill coefficient n=0.5.Results show emodin is a weak antagonist among natural compounds for TRPV1.The whole inhibition process is reversible,emodin exhibits no hypersensitization.Besides,sediment can be detected in the ORi solution when concentration of emodin reaches up to 50—60 μmol/L.We suggest that the inhibition of TRPV1 may contribute to the analgesic effect of Rhubarb extracts,and emodin may form the basis for developing new analgesic drugs.

关 键 词：TRPV1通道电流 辣椒素 大黄素 镇痛机制 双电极电压钳 

分 类 号：Q27[生物学—细胞生物学]