异丙肾上腺素对豚鼠离体心室肌细胞延迟整流钾电流的影响(英文)  

Effects of isoprenaline on delayed rectifier potassium current in isolated guinea pig ventricular myocytes

作　　者：崔毅[1] 赵德化[1] 

机构地区：[1]第四军医大学药理教研室

出　　处：《中国药理学报》1995年第6期502-504,共3页Acta Pharmacologica Sinica

摘　　要：观察异丙肾上腺素对豚鼠离体心室肌细胞延迟整流钾电流(I_K)的作用.方法:分离单个离体豚鼠心室肌细胞,采用电压钳技术观察I_K.结果:在用不同去极化时程脉冲(40—300ms)激活I_K的条件下,异丙肾上腺素(1 μmol·L^(-1))仅增加长时程脉冲(150—300 ms)激活的I_k,这一作用在预先用BAPTA缓冲细胞内钙的条件下仍然存在,而细胞内注射BAPTA则降低长时程脉冲激活的I_K.结论:豚鼠离体心室肌细胞I_K有二个成分,其中一个成分受异丙肾上腺素和细胞内钙的调控.To study the effects of isoprenaline (Iso) on the delayed rectifier potassium current (Ik) in isolated guinea pig ventricular my-ocytes. METHODS: Single cells were isolated from guinea pig ventricle.Ik was studied under voltage clamp conditions. RESULTS: When Ik was activated by depolarizing pulses to +40 mV of increasing duration (40-300 ms ) , Iso 1 umol.L-1 caused an enhancement in /k which was larger for longer pulses (150 - 300 ms). This was also seen when the intracellular calcium was buffered by l,2-bis(2-aminophenoxy ) ethane-N,N, N',N'-tetra-acetic acid (BAPTA). Intracellular application of BAPTA caused a decrease in Ik activated by longer pulses. CONCLUSION:There were two components of Ik, one of which was modulated by Iso and intracellular Ca2+.

关 键 词：异丙肾上腺素 钙 心肌 钾通道 

分 类 号：R965.2[医药卫生—药理学]