【作者】 李庆霞；

【导师】 金荫昌； 张德昌；

【作者基本信息】 中国协和医科大学 ， 分子药理学， 1997， 博士

【摘要】 近年来的研究表明，阿片受体对其效应体系有双相调节作用。例如除了早已为人熟知的抑制性作用之外，对腺苷酸环化酶、钙通道等还有兴奋作用。但对双相作用发生的条件，各项发生的机理及其生物学意义所知甚少。甚至某些效应体系（例如钾离子通道）是否存在双相调节都未有定论。本实验采用膜片箝全细胞记录法，研究NG108-15细胞系钾通道、钙通道的电生理特性，μ，κ，δ阿片受体相对特异激动剂DPDPE、U₅₀₄₈₈、OMF对延迟整流钾通道的双向调节作用，并探讨了双相调节作用与G蛋白调节作用的关系。 1、NG108-15细胞钾通道、钙通道的电生理特性 （1）将NG108-15细胞膜电位钳制在-90mV，给予时程为150ms的阶跃脉冲刺激，由-50mV逐渐增至+80mV，每次递增10mV。可记录到一系列外向电流，电流达稳态之后，不随时间失活。随着刺激电压增加，电流幅值不断增大，能够被10mM TEA抑制。以上结果显示该外向电流为延迟整流钾电流。依据激活时间常数，失活时间常数不同，将延迟整流钾电流可分为三类：快速激活、不随时间失活的钾电流；缓慢激活、不随时间失活的钾电流；缓慢激活、缓慢失活的钾电流。（2）灌流液中应用TTX阻断钠电流、TEA阻断钾电流之后，可记录到一缓慢激活、缓慢失活的内向电流，即为钙电流。在钳制电压为-80mV时，大部分细胞（12／20）的钙电流含有两种成分：其一在-40mV时开始出现，-20mV时更多还原

【Abstract】 In order to understand the mechanisms of the opioid receptor mediated signal transduction, the opioid receptor agonists induced biphasic regulation of delayed rectifier potassium channels in NG108-15 cells, and the possible involvement of G protein in this regulation were studied in this work.1. The electric characteristics of K⁺, Ca²⁺ channels in NG108-15.For the convenience of using NG108-15 cells as a model system for the investigation of the mechanisms underline the coupling of opioid receptors and ion channels, the electric characteristics of potassium and calcium channels in this cell line were studied in our laboratory. A series of outward currents was evoked in NG108-15 cells by depolarizing voltage steps from -50 mV to +80 mV at holding potential of -90mV. This whole cell outward current, which was inhibited by 10mM TEA, increased with the enhance of command potential, and after reaching its steady-state, this current did not decrease with time. All these characteristics indicated that the outward current was delayed rectifier potassium current. This K⁺ current was further classified to three subtypes: rapidly activated K⁺ current without inactivation with time, slowly更多还原