Effect of SKF 525A on the release of nitric oxide and prostacyclin from endothelial cells.

The effect of SKF 525A on the endothelium-dependent relaxation of rabbit aortic rings and on the release of nitric oxide and prostacyclin from porcine aortic endothelial cells in culture was examined. SKF 525A (10-30 microM) inhibited acetylcholine- but not the calcium ionophore A23187-induced endothelium-dependent relaxation without affecting the release of endothelium-derived relaxing factor from endothelial cells stimulated with bradykinin. Higher concentrations of SKF 525A (30-200 microM) caused transient endothelium-dependent relaxation of rabbit aortic rings and the release of nitric oxide and prostacyclin from the endothelial cells without inducing release of lactate dehydrogenase. The mechanism whereby SKF 525A releases nitric oxide and prostacyclin from endothelial cells requires further investigation.