麻黄碱抑制支气管平滑肌细胞增殖的机制

Mechanism of Ephedrine Inhibiting Proliferation of Bronchial Smooth Muscle Cells

BK通道(large-conductance Ca2+-activated K+ channel)是一种大电导、电压和钙离子依赖的钾通道,存在于哺乳动物几乎所有的组织中。β1亚基是首次从平滑肌细胞中分离到的一种BK通道辅助亚基。麻黄作为一种β肾上腺素受体激动剂,是一味治疗哮喘的常用中药。利用RT-PCR和膜片钳等技术,研究麻黄治疗哮喘的作用机制。结果表明:麻黄碱(ephedrine,Eph)作为麻黄的一种主要成分,显著抑制支气管平滑肌细胞(bronchial smooth muscle cells,BSMCs)的增殖和BK通道β1亚基的表达,但是对BK通道的电流没有显著影响。

BK channel is a kind of big conductance, voltage and Ca^2＋-activated potassium channel which exists in almost all tissues in mammal. The β1 subunit was first detected as an ancillary subunit of BK channel in smooth muscle cells and had significant influence on the biophysical properties of BK channel. Mahuang, as a β- adrenergic receptor agonist, is a Chinese traditional medicine treated as asthma. In this paper, RT-PCR and patch clamp were used to approach the mechanism of Mahuang treated on asthma, The finding results showed： Ephedrine which was the most components of Mahuang suppressed the proliferation of bronchial smooth muscle cells （BSMCs） and restrained the expression of β1 subunit of BSMCs. But, ephedrine had little effect on the current amplitude of BK channel.