Ligustrazine potently inhibits hypoxic pulmonary vasoconstriction. This effect can be mimicked by the sulphonylurea tolbutamide, a blocker of ATP-sensitive K+ channels. Here we demonstrate that ligustrazine is a specific blocker of ATP-sensitive K+ channels in mouse pancreatic β cells. This suggests that ligustrazine may act in the pulmonary circulation by blocking ATP-sensitive K+ channels.
