- 作者: Ming-Jai Su; Jo-Feng Chi; Shu-Hsun Chu
- 作者服務機構: a Pharmacological Institute and; b Department of Surgery, College of; Medicine, National Taiwan University, Taipei, Taiwan, ROC
- 中文摘要: --
- 英文摘要: The adrenergic modulation of inwardly rectifying and depolarization-acti- vated outward potassium currents was studied in single cardiac myocytes obtained from the human atrium. Membrane currents were recorded in enzy- matically dissociated cells using the whole-cell voltage-clamp technique.It was observed that, in the presence or absence of atenolol (or 1 μM propranolol), 30 μM phenylephrine attenuated inwardly rectifying and depolarization-acti- vated outward potassium currents including both transient and late-activated current. This suppressant effect of phenylephrine could be prevented by pre- treatment with an α-adrenoceptor antagonist. Isoproterenol (30μM) in- creased the late outward potassium current and net transient outward current. It is concluded that, in human atrial myocytes,α-adrenergic activation reduces depolarization-activated transient and late outward potassium current and inwardly rectifying background potassium current. β-Adrenergic activation resulted in an increase in the depolarization-activated transient and late out- ward potassium current.
- 中文關鍵字: --
- 英文關鍵字: Human atrial myocytes; Potassium currents; Adrenergic modulation; Phenylephrine; Isoproterenol