Stabilization and partial characterization of endothelium-derived relaxing factor from cultured bovine aortic endothelial cells.

The extreme lability of the chemically undefined vasoregulatory mediator, endothelium-derived relaxing factor (EDRF), has been overcome. The activity of EDRF, from cultured bovine aortic endothelial cells stimulated with A23187, was stabilized by acidification. An additional action of EDRF, platelet disaggregation was used as a sensitive and convenient bioassay to monitor purification. EDRF appears to be a hydrophilic molecule, rapidly inactivated under alkaline conditions. However, activity is restored upon reacidification suggesting that this instability results from a readily reversible chemical process. The stabilization and partial purification of EDRF sets the stage for its further biochemical and chemical characterization.