ABSTRACT
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.
Subject(s)
Angiotensin II/pharmacology , Biogenic Monoamines/pharmacology , Coronary Vessels/metabolism , Endothelium, Vascular/metabolism , Oxygen/pharmacology , Peptides/metabolism , Animals , Cattle , Cells, Cultured , Coronary Vessels/drug effects , Endothelins , Endothelium, Vascular/drug effects , Epinephrine/pharmacology , Histamine/pharmacology , Norepinephrine/pharmacology , Serotonin/pharmacology , Vasoconstriction/drug effectsABSTRACT
Endothelial cells were harvested by the collagenase perfusion of isolated mesenteric arteries of rats and cultured. An endothelin peptide was detected in the supernatant of these cells by an antibody which recognizes ET-1 but not "rat" endothelin (ET-3). Culture media was extracted using a C-8 solid phase column and subjected to reverse phase HPLC using a system that separates all known endothelins and immunoreactive endothelins measured using another antibody which recognizes all endothelins. The main immunoreactive peak co-eluted with ET-1. We could not detect any ET-2, ET-3 or Vasoactive Intestinal Contractor. A smaller immunoreactive peak of unknown structure that eluted earlier than ET-1 was also detected. In conclusion, rat endothelial cells secrete a peptide of similar chromatographic and immunoreactive properties as ET-1.
