Effect of an ATP sensitive potassium channel opener, levcromakalim, on coronary arterial microvessels in the beating canine heart

Abstract

Levcromakalim heterogeneously dilates coronary arterial microvessels via the opening of ATP sensitive potassium channels, and small vessels are more sensitive to levcromakalim.

Effects of Prostaglandin E1 on Vascular ATP-Sensitive Potassium Channels

“…25,26 A number of physiological studies have also demonstrated that vascular K ATP channels are involved in the maintenance of resting blood flow in a number of vascular beds, notably the coronary circulation, and in vasodilatation in response to metabolic demand. 8,21,27 These results indicate that PGE 1 -induced vascular K ATP channel activation may have advantageous properties, especially under ischemic conditions like angina pectoris. Further studies are necessary to clarify the influence of exogenously administered PGE 1 on vascular K ATP channels during clinical treatment.…”

Testosterone Relaxes Isolated Human Radial Artery by Potassium Channel Opening Action

“…For example, it was reported that adenosine, a metabolic regulator of coronary blood flow (probably via activating K ATP channels and inhibiting L-type Ca 2+ current), preferentially blocked the action potential in the small coronary artery, but had no effect on the action potential in the large coronary artery (38). Similarly, the coronary dilating actions of a K ATP -channel-opening drug, levcromakalim, were heterogeneous, and small resistant coro-nary arteries were more sensitive to this drug (39). It was also reported that the resting tone of large conductance vessels was little affected by GLI, whereas that of small resistance vessels was affected (40,41).…”

KATPChannels in the Cardiovascular System

“…Opening of K NDP channels hyperpolarizes smooth muscle cells, which leads to less Ca 2ϩ entry, vasodilation, and increased blood flow (649) (FIGURE 11). The contribution of K NDP channels to regulating the membrane potential of smooth muscle cells (and thus blood flow) increases as the coronary diameter decreases along the vascular bed (7,106,198,447,587,691), consistent with a significant role for K ATP channels in the smaller resistance vessels (686). Their contribution to the regulation of coronary function was first identified by the vasodilatory actions of K ATP channel openers (290, 649, 682) and the vasoconstrictive effects of K ATP channel blockers (424).…”