Conduction of nitric oxide synthesis and intracellular nonheme iron-nitrosyl complexes in murine cytokine-treated fibroblasts

Abstract Murine fibroblasts treated with interferon-γ plus tumor necrosis factor-α plus lipopolysaccharide produce nitrite and EPR-observable intracellular nonheme iron-thiol-dinitrosyl species. Inhibition of . NO synthesis or de novo tetrahydrobiopterin (BH 4 ) synthesis decreases nitrite and the EPR signal. The effects of BH 4 synthesis inhibition are prevented by sepapterin, which increases BH 4 through the salvage pathway.