BAY 11-7082, an inhibitor of nuclear factor-kappaB (NF-kappaB), which prevents a step of the phosphorylation of inhibitory protein IkappaB bound to NF-kappaB, suppressed basal and tumor necrosis factor (TNF)-alpha-induced prepro endothelin (ET)-1 mRNA expression and NF-kappaB activation in cultured vascular endothelial cells. BAY 11-7082 significantly decreased basal and TNF-alpha-induced ET-1 release from endothelial cells. These results indicate that the inhibition of NF-kappaB activation contributes to the suppressive effect of BAY 11-7082 on ET-1 gene expression and ET-1 release, thereby suggesting that NF-kappaB plays an important role in the regulation of ET-1 production.