吗啡对豚鼠支气管平滑肌Kv通道的影响

目的探讨吗啡对豚鼠支气管平滑肌(guinenpigbron-chialsmoothmuscle,GPBSM)Kv通道的影响。方法用全细胞膜片钳技术研究吗啡对急性分离GPBSMKv(电压依赖性延迟整流钾通道)活性的影响,用Westernblot和RT-PCR技术,通过图像分析系统和凝胶成像系统分析吗啡对体外培养GPBSM的Kv1·5mRNA及蛋白质表达的影响。结果吗啡能抑制急性分离GPBSM的Kv通道电流和抑制抑制培养GPBSMKv1·5mRNA及蛋白质的表达,吗啡受体阻断剂盐酸纳洛酮和PKC阻断剂Ro31-8220能明显阻止这种效应。结论吗啡收缩支气管平滑肌可能是活化支气管平滑肌细胞膜的PKC,从而抑制其cAMP介导的Kv通道电流活性,下调Kv1·5mRNA及蛋白质表达水平完成的。

Effect of morphine on the Kv channel in bronchial smooth muscle in guinea-pigs

Aim To explore the effect of the morphine(MP) on the Kv channel in bronchial smooth muscle in guinea-pigs (GPBSM) and expressions of the Kv 1.5 mRNA and protein . Methods The effect of the MP on the Kv channel was studied by patch clamp recording in GPBSM and expressions of the Kv 1.5 mRNA and protein were measured by Western-blot and RT-PCR techniques. Results Morphine remarkably restrained the Kv channel current and the expression of the Kv 1.5 mRNA and protein in cultured GPBSM (n=6, each group, P<0.05 vs control).These effects were remarkably blocked by the naloxone (NL) and Ro31-8220. Conclusion MP induced the GPBSM contraction by activating PKC of cell membrane to restrain the current activity of the Kv channel which was mediated by cAMP, and reducing expressions of Kv 1.5 mRNA and protein.