【摘要】 目的通过研究冈田酸对大鼠三叉神经元电压门控性钾、钙电流的影响,探讨磷酸酯酶在细胞信号转导中的调节作用。方法采用全细胞膜片钳方法。结果冈田酸1μmol.L-1对瞬时外向钾电流(IA)的抑制率为28.6%,对延迟整流钾电流(IK)和钙电流(ICa)的增加率分别为22.7%和20.0%。冈田酸1μmol.L-1使IA和IK的激活曲线以及IA的失活曲线发生超级化位移,对ICa激活和失活曲线的影响没有统计学意义。结论①蛋白丝/苏氨酸磷酸酯酶1和2A可能参与了大鼠三叉神经节神经元电压门控性钾和钙通道的调节。②电压门控性钾和钙通道对蛋白丝/苏氨酸磷酸酯酶1和2A的去磷酸化反应表现出不同的依赖性。更多还原

【Abstract】 AIM To investigate the effects of serine/threonine protein phosphatases in regulation of cell signal transduction on voltage-gated potassium and calcium channels in cultured rat trigeminal ganglion(TRG)neurons.METHODS Whole-cell patch clamp technique was used to record the potassium and calcium currents from adult rat TRG neurons before and after perfusion of okadaic acid,a potent inhibitor of the serine/threonine protein phosphatases 1 and 2A.RESULTS Okadaic acid 1 μmol·L-1 inhibited transient outwards potassium currents(IA)by 28.6%,increased delay rectified potassium currents(IK)and calcium currents(ICa)by 22.7% and 20.0%,respectively.okadaic acid 1 μmol·L-1 produced significant hyperpolarizing shifts in the conductance-voltage(G-V)curves and inactivation curves of IA,also produced significant hyperpolarizing shifts in the G-V curves of IK,while it had no effect on the activation and inactivation kinetics of ICa.CONCLUSION Serine/threonine protein phosphatases 1 and 2A may be involved in the modulation of voltage-gated potassium and calcium channels on rat TRG neurons.In addition,voltage-gated potassium and calcium channels show different dependence on the dephosphorylation reactions of PP1 and PP2A phosphatases.更多还原