Chinese Med J Peking
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Chinese Med J Peking · Jan 2005
Effect of mitochondrial KATP channel on voltage-gated K+ channel in 24 hour-hypoxic human pulmonary artery smooth muscle cells.
Hypoxic pulmonary hypertension (HPH) is initiated by inhibition of O2-sensitive, voltage-gated (Kv) channels in pulmonary arterial smooth muscle cells (PASMCs). The mechanism of hypoxic pulmonary hypertension has not yet been fully elucidated. The mitochondrial ATP-sensitive K+ channel (MitoKATP) is extremely sensitive to hypoxia, and is a decisive factor in the control of mitochondrial membrane potential (DeltaPsim). This study investigated the changes of cell membrane potential and Kv channel in cultured human pulmonary artery smooth muscle cell (hPASMC) exposed to 24 hour-hypoxia, and explored the role of MitoKATP and DeltaPsim in this condition. ⋯ The opening of MitoKATP followed by a depolarization of DeltaPsim in hypoxia might contribute to the alterations in the expression of cell membrane Kv1.5 mRNA and protein leading to change in the cell membrane potential of hypoxic hPASMCs. This might be a mechanism of the development of hypoxic pulmonary hypertension.