Endothelium-Derived Hyperpolarizing Factor-Fact or Fiction?
The vascular endothelium releases a diffusible factor that hyperpolarizes and hence relaxes vascular smooth muscle cells predominantly through activation of Ca(2+)-dependent K(+) channels. In the coronary circulation, this endothelium-derived hyperpolarizing factor appears to be a cytochrome P(450)-derived arachidonic acid epoxide, the release of which may play a crucial role in the maintenance of coronary blood flow in arteriosclerosis.
Hecker
Markus
M
Director of the Department of Cardiovascular Physiology, University of Goettingen, Humboldtallee 23, 37073 Goettingen, Germany.