Endothelium-derived relaxing factor

The Endothelium-derived relaxing factor (EDRF) is a strong vasodilator produced by cardiac endothelial cells in response to stress signals such as high levels of ADP accumulation or hypoxia.

[citation needed] Robert F. Furchgott is widely recognised for this discovery, even going so far as to be a co-recipient of the 1998 Nobel Prize in Medicine with his colleagues Louis J. Ignarro and Ferid Murad.

[citation needed] EDRF is produced from L-arginine by an enzyme (endothelial nitric oxide synthase) that is dependent on calcium-calmodulin and NADPH - this occurs in the cardiac endothelium.

[citation needed] EDRF then diffuses to the smooth muscle in vascular tissue (vessels may be large or small), here it enacts endogenous vasodilation.

[citation needed] The NO compound is also capable of reducing clotting in the blood stream due to its ability to prevent platelet adhesion and aggregation.