Protective Effects of Anesthetics on Vascular Function Related to K+ Channels

K+ channels play an essential role in the membrane potential of arterial smooth muscle, and also in regulating contractile tone. Especially, in vascular smooth muscle, the opening of adenosine triphosphate (ATP)-sensitive K+ (K-ATP) channels leads to membrane hyperpolarization, resulting in muscle relaxation and vasodilation. This activation also plays a role in tissues during pathophysiologic events such as ischemia, hypoxia, and vasodilatory shock. In this review, we will describe the physiological and pathophysiological roles of vascular smooth muscle K-ATP channels in relation to the effects of anesthetics. Although accumulated evidence suggests that many anesthetics modify the above function of K+ channels as a metabolic sensor, further studies are certainly needed to resolve certain issues, especially in clinical settings of anesthesia use.