Episodic coronary artery vasospasm and hypertension develop in the absence of Sur2 KATP channels

Abstract
KATP channels couple the intracellular energy state to membrane excitability and regulate a wide array of biologic activities. KATP channels contain a pore-forming inwardly rectifying potassium channel and a sulfonylurea receptor regulatory subunit (SUR1 or SUR2). To clarify the role of KATP channels in vascular smooth muscle, we studied Sur2 gene-targeted mice (Sur2–/–) and found significantly elevated resting blood pressures and sudden death. Using in vivo monitoring, we detected transient, repeated episodes of coronary artery vasospasm in Sur2–/– mice. Focal narrowings in the coronary arteries were present in Sur2–/– mice consistent with vascular spasm. We treated Sur2–/– mice with a calcium channel antagonist and successfully reduced vasospastic episodes.