Endothelin ETA receptor antagonist reverses the inhibitory effect of platelet-derived growth factor on cytokine-induced nitric oxide production

Cytokines and cytokine-induced nitric oxide (NO) play important roles in in flammatory glomerular diseases, and both platelet-derived growth factor and transforming growth factor-beta inhibit cytokine-induced NO production. In this study, we demonstrated that a selective endothelin ETA receptor antag onist, BQ-485 (Hexahydro-1H-azepinylcarbonyl-Leu-D-Trp-D-Trp-OH), reversed the inhibitory effect of platelet-derived growth factor on cytokine-induced NO production, but not that of transforming growth factor-beta. Our findin gs suggest. a difference between the inhibitory mechanisms of platelet-deri ved growth factor and transforming growth factor-beta on cytokine-induced N O production. (C) 1999 Elsevier Science B.V. All rights reserved.