Hypoxia increases endothelin release in bovine endothelial cells in culture, but epinephrine, norepinephrine, serotonin, histamine and angiotensin II do not.

Calf coronary artery endothelial cells in culture were exposed to normoxic and hypoxic conditions (2% oxygen) for 4 hr and 24 hr. After 24 hr of incubation, there was a significant increase in the accumulation of immunoreactive endothelin (irET) in the media. Incubations with epinephrine, norepinephrine, serotonin, histamine and angiotensin II did not result in an increase in irET production. These studies indicate that hypoxia enhances endothelin release, however, the kinetics of this release suggest that the acute endothelium-dependent vasoconstriction occurring after hypoxia does not result from an increase in endothelin release.