中国药理学通报2012，Vol.28Issue(7)：947-951,5.DOI:10.3969/j.issn.1001-1978.2012.07.015
豚鼠心室肌细胞延迟整流钾电流快慢成分在生长发育过程中的变化
Developmental changes in rapidly and slowly activating delayed rectifier potassium currents in guineapig ventricular myocytes
摘要
Abstract
Aim To characterize the developmental changes in rapid and slow component of delayed rectifi -er potassium currents (Ikr, Iks ) and action potential in guinea pig ventricular myocytes. Methods Single ventricular myocytes isolated from neonatal, young and a- dult guinea pig heart were dissociated by enzymatic dis -persion. (l)The total delayed rectifier potassium current ( IK ) was first recorded with whole-cell patch-clamp technique at room temperature. The Iks was then recorded as the same pulse protocol after adding a spe -cific Ikr channel blocker E-4031 to the external solution. The Ikr was obtained by subtracting Iks tail from IK tail current. ( 2 ) The action potentials were recorded at 1 Hz with perforated patch clamp. Results ( 1 ) Both Ikr and Iks current densities were increased during the developmental period, but they showed different growth pattern. The current densities for Iks were significantly enhanced at most of depolarizing step pre -pulses between neonatal and young periods and be -tween young and adult periods. A significant up regulation in the current density of Ikr was observed in young myocytes compared with neonatal ones , while there was no substantial change between young and a -dult periods. (2) The APD90 in guinea pig ventricular myocytes was significantly prolonged from the neonate to the adult periods. Conclusion (1) The current densities of Ikr and Iks are up regulated in a different pattern in guinea pig ventricular myocytes during the development from the neonate to the adult. ( 2 ) The action potential duration under goes a significant pro -longation during postnatal life despite of the developmental increment in repolarizing K , suggesting an up- regulation of depolarizing current in guinea pig ventric -ular myocytes during the developmental period .关键词
发育/心肌细胞/豚鼠/延迟整流钾电流/动作电位/膜片钳技术Key words
development/ cardiomyocytes / guinea-pig/ delayed rectifier potassium current/ action potential/ patch-clamp technique分类
医药卫生引用本文复制引用
朱晓冉,东蕾,许彦芳..豚鼠心室肌细胞延迟整流钾电流快慢成分在生长发育过程中的变化[J].中国药理学通报,2012,28(7):947-951,5.基金项目
国家自然科学基金资助项目(No 30871010) （No 30871010）
