Department of Physiology, School of Basic Medical Sciences, Department of Respiratory Medicine, Capital Medical University, Beijing 100069, China.
Physiol Res. 2009;58(5):645-652. doi: 10.33549/physiolres.931594. Epub 2008 Nov 4.
Regulatory volume decrease (RVD) is essential for the survival of animal cells. The aim of this study was to observe the RVD process in rat ventricular myocytes, and to determine if the K(ATP) channels are involved in the RVD process in these cells. By using reverse transcriptase polymerase chain reaction and Western blot analysis, we demonstrated that there are two types of K(ATP) channels expressed in rat ventricular myocytes: Kir6.1 and Kir6.2. When rat cardiac myocytes were exposed to hypotonic solution, cell volume increased significantly within 15 min and then gradually recovered. This typical RVD process could be inhibited by a Cl(-) channel blocker (0.5 mM 9-anthracene-carboxylic acid?9-AC), a K(+) channel blocker (5.0 mM CsCl) and a K(ATP) channel blocker glibenclamide (10 microM). Electrophysiological results showed that hypotonic solution activated a whole-cell current, which had similar biophysical characteristics with K(ATP) opener (pinacidil)-induced currents. This current could be blocked by glibenclamide. Our data suggested that the RVD process in rat ventricular myocytes is dependent on the activation of K(+) channels, and that K(ATP) channels are involved in this process.
调节性容积减少（RVD）对动物细胞的生存至关重要。本研究旨在观察大鼠心室肌细胞的 RVD 过程，并确定 K(ATP)通道是否参与这些细胞的 RVD 过程。通过逆转录聚合酶链反应和 Western blot 分析，我们证明了大鼠心室肌细胞中表达了两种类型的 K(ATP)通道：Kir6.1 和 Kir6.2。当大鼠心肌细胞暴露于低渗溶液时，细胞体积在 15 分钟内显著增加，然后逐渐恢复。这种典型的 RVD 过程可以被 Cl(-)通道阻滞剂（0.5 mM 9-蒽羧酸-9-AC）、K(+)通道阻滞剂（5.0 mM CsCl）和 K(ATP)通道阻滞剂格列本脲（10 μM）抑制。电生理结果表明，低渗溶液激活了一种全细胞电流，其具有与 K(ATP)开放剂（吡那地尔）诱导的电流相似的生物物理特性。该电流可被格列本脲阻断。我们的数据表明，大鼠心室肌细胞的 RVD 过程依赖于 K(+)通道的激活，并且 K(ATP)通道参与了这一过程。
