Nuclear factor-kappaB inhibitors abolish hypoxic vasoconstriction in sheep-isolated pulmonary arteries

The aim of this study was to determine the role of nuclear factor-kappaB (NF-kappaB) in hypoxic constriction of isolated pulmonary arteries. Rings were suspended in an organ bath filled with Krebs-Henseleit solution and isometric contractions were recorded continuously. Hypoxia (%95 N(2)-%5 CO(2)) had no marked effect on resting force in artery rings. However, hypoxia caused further contractions in serotonin-precontracted arteries. Hypoxia-induced vasoconstrictions were abolished by preincubation with NF-kappaB inhibitors, pyrrolidine dithiocarbamate (100 microM) or pyrithione (10 microM). These results suggest that reactive oxygen species and/or NF-kappaB activation may be involved in the hypoxia-induced vasoconstriction in sheep-isolated pulmonary arteries.