4℃预处理对人中性粒细胞膜电流和极性的影响
袁春华, 蔡春青, 邹飞*
南方医科大学公共卫生与热带医学学院,广州 510515
摘要
对急性分离的人中性粒细胞采用4℃预处理是进行膜片钳实验前经常采取的步骤,但这一步骤对电生理记录结果有何影响尚无文献报道。本实验探讨这一步骤对电生理记录过程和实验结果的影响。结果显示,4℃预处理可以显著提高细胞的封接率,有利于对中性粒细胞进行电生理记录;封接率提高的原因与4℃预处理降低细胞的极性活动有关,但记录到的电压依赖性钾通道全细胞电流和大电导Ca2+ 依赖性K+ 单通道电流动力学没有显著的变化。这些结果表明,4℃预处理可能影响到细胞膜上与极性有关的脂膜变化,但对细胞膜上蛋白的功能影响较少。
关键词:
中性粒细胞; 极性; 膜片钳技术
Effect of 4 ºC pretreatment on the membrane current and cell polarity in humanneutrophils
YUAN Chun-Hua, CAI Chun-Qing, ZOU Fei*
School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China
Abstract
To investigate the role of ion channels in the coupling responses of neutrophils to extracellular stimulus, it is necessary tostudy the membrane ion channel activities using patch-clamp technique. However, little has been known about the ion channel activitiesin neutrophils due to the difficulties in forming giga-seal with pipettes because of small diameter of neutrophils and the easily developedpolarization. Some studies indicated that favorable results could be achieved through pretreatment at low temperature before electrophysiologicalrecordings. But it remains unclear whether the pretreatment affects the membrane current and why the seal rate increasesafter low temperature pretreatment. The purpose of this study was to investigate the effects of 4 ºC pretreatment on the membranecurrent and cell polarity in human neutrophils. In the experiments, human neutrophils were isolated from fresh peripheral blood ofhealthy volunteers and divided into two groups (room temperature group and 4 ºC pretreatment group). Voltage-dependent K+ (Kv)currents were recorded in whole-cell voltage-clamp mode and large-conductance Ca2+-activated K+ (BKCa) currents were recorded usinginside-out patches. The results showed that 4 ºC pretreatment significantly inhibited cell polarity (P<0.05), and it took more time forneutrophils to form a polarity-cycle [(534±32) s, n=20] compared with those at room temperature [(257±24) s, n=20]. Meanwhile,seal rate significantly increased in 4 ºC pretreatment group (64%) compared with that in the room temperature group (27.5%). The sealrate and cell polarity rate during 0~1 min after 4 ºC pretreatment were significantly different from those at room temperature, while nosignificant difference was found during 9~10 min between the two groups. Our results suggest that 4 ºC pretreatment can inhibit cellpolarity and increase seal rate, but has no effects on membrane currents. It is also suggested that 0~1 min after 4 ºC pretreatment is amore suitable time for electrophysiological recording in neutrophils.
Key words:
Neutrophils; polarity; patch-clamp technique
收稿日期: 录用日期:
通讯作者:邹飞 E-mail: zfei@fimmu.com
引用本文:
袁春华, 蔡春青, 邹飞. 4℃预处理对人中性粒细胞膜电流和极性的影响[J]. 生理学报 2006; 58 (5): 494-499.
YUAN Chun-Hua, CAI Chun-Qing, ZOU Fei. Effect of 4 ºC pretreatment on the membrane current and cell polarity in humanneutrophils. Acta Physiol Sin 2006; 58 (5): 494-499 (in Chinese with English abstract).