Progress on the characterization and identification of endothelium‐derived relaxing factor(s)

Substantial evidence indicates that there are novel factors released from the vascular endothelium that regulate vasodilatation. The weight of the present evidence is that endothelium-derived relaxing factor(s) (EDRF) is an oxidation product of arachidonic acid. Whether the oxidative enzyme is a lipoxygenase or related to a cytochrome P450 monooxygenase remains under investigation. Future progress requires a reproducible source of EDRF to allow isolation, purification, and structural identification.