Exercise training changes the gating properties of large-conductance Ca2+-activated K+ channels in rat thoracic aorta smooth muscle cells.
Exercise training changes the gating properties of large-conductance Ca2+-activated K+ channels in rat thoracic aorta smooth muscle cells.
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DOI：
10.1016/j.jbiomech.2009.08.035
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发表时间：
2010-01
影响因子：
2.4
通讯作者：
Hucheng Zhao;Fa Wang
中科院分区：
文献类型：
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作者：
Hucheng Zhao;Fa Wang
大电导钙激活钾通道（BKCa）在调节细胞对血流变化的兴奋性中起着关键作用。已经证明，人和大鼠的血管BKC通道电流在运动训练后增加。动脉肌细胞中BKCa通道活性的上调可能代表了限制血管对运动训练反应性的细胞代偿机制。然而，其潜在机制尚未完全了解。在本研究中，我们研究了大鼠胸主动脉平滑肌细胞中BKC通道的单通道活性和动力学。结果表明，运动训练显著增加了细胞的开放概率（Po），缩短了细胞的平均闭合时间，增加了细胞的平均开放时间，提高了细胞对Ca ~（2+）和电压的敏感性，而不改变细胞的单位电导和K ~+选择性。我们的结果表明了一种新的机制，运动训练通过改变BKCachanel的活动和动力学来增加K+电流。
Large-conductance Ca2+-activated K+(BKCa) channels play a critical role in regulating the cellular excitability in response to change in blood flow. It has been demonstrated that vascular BKCachannel currents in both humans and rats are increased after exercise training. This up-regulation of the BKCachannel activity in arterial myocytes may represent a cellular compensatory mechanism of limiting vascular reactivity to exercise training. However, the underlying mechanisms are not fully understood. In the present study, we examined the single channel activities and kinetics of the BKCachannels in rat thoracic aorta smooth muscle cells. We showed that exercise training significantly increased the open probability (Po), decreased the mean closed time and increased the mean open time, and the sensitivity to Ca2+and voltage without altering the unitary conductance and the K+selectivity. Our results suggest a novel mechanism by which exercise training increases the K+currents by changing the BKCachannel activities and kinetics.