激动TRPV4受体对大鼠三叉神经节神经元电压依赖性钠电流的影响

发布时间：2018-04-17 02:10

  本文选题：TRPV4 + 膜片钳　； 参考：《华中科技大学》2006年硕士论文

【摘要】： TRPV4是作为低渗透压激活的渗透压感受器被发现的。Phorbol ester 4a-phorbol 12,13-didecanoate(4аPDD)是一种合成佛波脂,它是一种非蛋白磷脂酶C途径激活通道的佛波脂类,对TRPV4有强效的特异性的激动作用。渗透压和佛波脂两者的通道激活机制还未曾清楚。现已明确TRPV4是一种非选择性的外向整流阳离子通道,对钙离子和钠离子都有通透性,钙钠的通透比值为5~7。TRPV4受体激动可以引起细胞内钙离子浓度的增加,对钠离子的影响还未见相关文献报道。本实验拟用低渗和4аPDD刺激TRPV4来观察钠电流的变化。 (1)应用全细胞膜片钳技术,在培养的大鼠三叉神经节神经元上记录低渗外液对细胞膜电压依赖性钠电流的影响。结果表明:低渗外液可浓度依赖性地抑制电压依赖性钠电流峰值。280mOsm,260mOsm,220mOsm分别抑制三叉神经节神经元电压依赖性钠电流峰值为24.2%±10.2% (n=6, P 0.05)和45.7%±15.6% (n=8, P 0.05)以及70.5%±18.1% (n=6, P 0.05),IC50为268mOsm。300mOsm,280mOsm,260mOsm,220mOsm对电压依赖性钠电流的翻转电位分别为28.0mV、22.7 mV、17.4mV、7.3 mV (n=6, P 0.05)。低渗外液对电压依赖性钠电流激活曲线无明显影响;左移失活曲线。300mOsm、280mOsm、260mOsm、220mOsm失活曲线拟合的半数失活电压,曲线的斜率因子分别为V1/2=-45.8±9.6mV,k=-17.54±6.9;V1/2=-47.2±7.8mV, k=-17.1±6.0 ;V1/2=-56.4±11.2mV, k=-14.4±5.8;V1/2=-60.6±10.8mV, k=-11.3±4.2 (n=6, P 0.05)。 (2)应用全细胞膜片钳技术,在培养的大鼠三叉神经节神经元上记录佛波脂4alphaPDD对细胞膜电压依赖性钠电流的影响。佛波脂4alphaPDD也可浓度依赖性地抑制大鼠三叉神经节神经元电压依赖性钠电流峰值。0.1,0.3,1,3,10μmol·L-1 4аPDD分别抑制三叉神经节神经元电压依赖性钠电流峰值24.68±7.2%(n=8, P 0.05),32.02±9.4%(n=7, P 0.05),52.7±12.2%(n=6, P 0.05),67.48±9.8%(n=7, P 0.05),73.9±14.6%(n=6, P 0.05),IC50为0.41μmol·L-1。0.1μmol·L-1 4аPDD对电压依赖性钠电流的电压依赖性、激活曲线、失活曲线均无明显影响。
[Abstract]:Phorbol ester 4a-phorbol 1213-didecanoate 4 (PDD) is a kind of synthetic phorbol lipids, which is a nonprotein phospholipase C pathway activator of phorbol lipids, which has a strong and specific activation effect on TRPV4.The mechanism of osmotic pressure and phorbol fat channel activation is not clear.It has been established that TRPV4 is a non-selective outward rectifier cation channel, which has permeability to both calcium and sodium ions. The permeability ratio of calcium and sodium is that the activation of 5~7.TRPV4 receptor can cause the increase of intracellular calcium ion concentration.The effect on sodium ion has not been reported.In this experiment, hypotonic and 4 PDD stimulation of TRPV4 were used to observe the changes of sodium current.1) the effects of hypotonic solution on the voltage-dependent sodium currents of rat trigeminal ganglion neurons were recorded by whole-cell patch clamp technique.The results showed that hypotonic solution could inhibit the peak value of voltage-dependent sodium current in a concentration-dependent manner. 280 m Osmon 260 m Osmon 220 mOsm in trigeminal ganglion neurons (24.2% 卤10.2%, P 0.05) and 45.7% 卤15.6% n8, P 0.05), and 70.5% 卤18.1% P0.05% IC50 in trigeminal ganglion neurons, respectively.The flipping potentials of the voltage-dependent sodium current for 280mOsm.300mOsm-280mOsm-220mOsm were 28.0mV ~ 22.7mV ~ 17.4mV ~ (7.3) MV ~ 7.3mV / n ~ (6), P = 0.05 ~ (-1), respectively.浣庢笚澶栨恫瀵圭數鍘嬩緷璧栨，

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