【作者】 马来记； 吕洛； 林惠芬； 魏少敏； 刘琳云； 焦松； 梅岩艾；

【Author】 Ma Laiji, Lu Luo, Lin Huifen, Wei Shaomin. Liu Linyun, Jiao Song, Mei Yanai Research and Development Center, Shanghai Jahwa United Co., Ltd.,shanghai, 200082 Life Science School, Fudan University, shanhai,200433

【机构】 上海家化联合股份有限公司技术中心； 复旦大学生命科学院；

【摘要】 目的:阐明B16黑素细胞离子通道属性,以及内皮素对其功能调节。方法:采用膜片箝技术的全细胞记录模式进行记录。结论:从B16细胞上记录到了电压依赖性延迟整流外向K+电流:细胞内液中 Ca2+能够抑制B16细胞的外向K+电流,细胞外液中生理浓度Mg2+能够改变该电流的激活特征;B16细胞的外向K+通道,被认为是一种Ca2+失活电压依赖性外向K+通道,可能由eag通道家族所介导。B16 细胞的外向K+通道对TEA不敏感,而对4-AP和ChTX敏感。ET-1可以引起该外向K+电流幅度降低, 是一种可逆性抑制。当电流恢复到对照水平后,重复给ET-1仍然能够产生反应,表明该K+通道对ET-1 反应无脱敏现象。G-蛋白偶联受体抑制剂PTX能够阻止B16细胞对ET-1的反应,说明ET-1对B16细胞外向K+通道的作用是经过受体进行的。PKC的特异性阻断剂H7也能够抑制ET-1这种作用的产生。更多还原

【Abstract】 Purpose: To probe the characteristics of ion channels in B16 murine melanoma cells and to investigate them modulated by endotheline-1. Methods: The ion channels were recorded using the patch-clamp technique with the whole-cell recording. Results and conclusion: we recorded the voltage-dependent outward K+ current in cultured B16 melanoma cells. When cells were loaded with a Ca2+-chelating agent (EGTA or BAPTA) the K+ current amplitude gradually increased with time after establishment of the whole cell configuration. Replacement of Ca2+ with Co2+ in the extracellular medium caused no significant modulation of the K+ current amplitude. ET-1 (10 nM) reversibly decreased the K+ current amplitude and accelerated the decay of the K+ current. The ET-1-induced inhibitory effect displayed no desensitization following repeated ET-1 application. Pretreatment with pertussis toxin (PTX) or perfusion of cells with the protein kinase C (PKC) inhibitor H-7 abolished the inhibitory effect of ET-1 on the K+ current. We conclude that the outward K+ current recorded in murine B16 melanoma cells may represent a Ca2+-inactivated K+ current, and that the inhibitory effect of ET-1 on the K+ current involves a PTX sensitive and PKC-dependent pathway.更多还原