氟康唑对豚鼠心室肌细胞I_K和在HEK-293细胞中表达的HERG钾通道的抑制作用  

Inhibition of delayed rectifier K^+ current in guinea pig ventricular myocytes and HERG K^+ channel expressed in HEK-293 cells by fluconazole

作　　者：韩圣娜[1] 陈秋[1] 张雨[1] 角灿武[1] 毛讯[1,2] 付润芳[1] 张莉蓉[1] 

机构地区：[1]郑州大学基础医学院药理学教研室,河南郑州450000 [2]漯河市医专药理学教研室,河南漯河462000

出　　处：《中国药理学通报》2010年第7期861-866,共6页Chinese Pharmacological Bulletin

基　　金：河南省重点攻关资助项目(No92102310225)

摘　　要：目的研究氟康唑对豚鼠心室肌细胞延迟整流钾电流(IK)和在HEK-293细胞中表达的HERG钾通道的抑制作用。方法应用酶解法消化豚鼠单个心室肌细胞,观察氟康唑对IK的影响;采用磷酸钙沉淀瞬时转染的方法将HERG基因表达于HEK-293细胞上,观察氟康唑对野生型HERG钾通道电流、激活和失活曲线的影响,以及氟康唑对Y652A和F656C突变型HERG钾通道的作用;IK和HERG电流的记录均采用全细胞膜片钳技术。结果氟康唑(0.01、0.1、1、3、10、30、100、300和1 000μmol.L-1)浓度依赖性地抑制IK和HERG钾电流,其IC50值分别为(68.1±21.6)μmol.L-1和(48.2±9.4)μmol.L-1,对HERG钾通道的电压依赖性激活和失活曲线无影响;与野生型(WT)比较,Y652A和F656C突变型可减弱氟康唑对HERG通道的阻断作用。结论氟康唑能阻断IK和HERG通道,Y652和F656是氟康唑与HERG通道结合的关键位点。Aim To study the inhibition of delayed rectifier K^＋ current（IK）in guinea pig ventricular myocytes and HERG K^＋ channel expressed in HEK-293 cells by fluconazole.Methods Whole-cell patch clamp technique was used to record IK in guinea-pig ventricular myocytes by collagenase dispersion and to record WT,Y652A and F656C HERG current expressed in HEK-293 cells by a calcium phosphate precipitation method.Results Fluconazole（0.01,0.1,1,3,10,30,100,300 and 1 000 μmol·L^-1）inhibited IK and HERG K^＋ current in a concentration-dependent manner,and the IC50 values were（68.1±21.6）μmol·L^-1 and（48.2±9.4）μmol·L^-1,respectively.But fluconazole did not markedly modify the activation and inactivation curves of HERG channel.Mutations in drug-binding sites（Y652A or F656C）of the HERG channel attenuated the HERG current blocked by fluconazole.Conclusion Fluconazole can block IK and HERG-K~＋ channel,and Y652 and F656 is the critical residue in the fluconazole-binding site.

关 键 词：氟康唑 延迟整流钾电流 HERG钾通道 膜片钳技术 HEK-293细胞 心室肌细胞 

分 类 号：R-332[医药卫生] R322.11