Research for oxygen sensitive ionic channels of human vascular smooth muscle cells.

本实验采用全细胞电压钳技术对人脐动脉平滑肌细胞的氧敏感性离子通道进行了研究，在实验期间（2002-2003年），我们发现了以下两个主要结果：1.人脐动脉平滑肌细胞的钙通道不受氧/缺氧的影响。我们用Ba^<2+>作为电荷载体，因为Ca^<2+>电流非常小，用于评估Ca通道。2.将外部溶液从含氧溶液改变为缺氧溶液，可以增加K通道。结果表明，ATP敏感性钾通道在人血管平滑肌细胞氧敏感性中起重要作用，Na/Ca交换体在氧诱导的血管收缩中的作用有待进一步研究。

We had explored the oxygen sensitive ionic channels of human umbilical vascular smooth muscle cells using whole-cell voltage clamp method.We have found the following two major results in the experimental years (2002-2003).1.Ca channel of the VMS cells from umbilical artery was not modified by oxygen/hypoxia. We used the Ba^<2+> as a charge carrier because Ca^<2+> current was very small for evaluating the Ca channel.2.K channel was increased by changing the external solution from oxygenated to hypoxic solution. The increased currents were completely inhibited by glybenclamide indicating that the increased currents were ATP-sensitive K channel currents.These results were indicating that ATP-sensitive channel may play an important role for oxygen sensitivity of the human vascular smooth muscle cells.We will evaluate the contribution of the Na/Ca exchanger which also play an important role for oxygen-induced contraction of vasculature as a next project.