Pyrrolidine dithiocarbamate inhibits induction of nitric oxide synthase activity in rat alveolar macrophages

Biochem Biophys Res Commun. 1993 Mar 31;191(3):1301-8. doi: 10.1006/bbrc.1993.1359.


Since nuclear factor kappa B (NF-kappa B) is activated during many inflammatory conditions, we assessed its role in expression of the L-arginine-nitric oxide pathway by rat alveolar macrophages. Pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-kappa B activation, was added to cultured macrophages stimulated with lipopolysaccharide (LPS) and interferon-gamma (IFN gamma). Inducible nitric oxide synthase (iNOS) activity was determined by measuring the stable nitrogen oxide end products of L-arginine oxidation: nitrite (NO2-) and nitrate (NO3-). Ten, 25 and 50 microM PDTC progressively inhibited iNOS activity by macrophages. When 50 microM PDTC was added 2 h before LPS + IFN gamma, L-arginine oxidation by macrophages was inhibited by > 99%; L-arginine oxidation was reduced by 70% if 50 microM PDTC and the stimuli were introduced together; NO2- and NO3- were not decreased significantly if 50 microM PDTC was added 6 h after LPS + IFN gamma. Cycloheximide added along with LPS + IFN gamma totally inhibits iNOS activity, while cycloheximide added 6 h after LPS + IFN gamma did not reduce NO2- and NO3- in tissue culture supernatants. These findings suggest iNOS activity in macrophages treated with LPS + IFN gamma requires NF-kappa B activation.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Oxidoreductases / biosynthesis*
  • Animals
  • Cells, Cultured
  • Cycloheximide / pharmacology
  • Enzyme Induction / drug effects
  • In Vitro Techniques
  • Macrophages, Alveolar / enzymology*
  • NF-kappa B / metabolism
  • Nitric Oxide Synthase
  • Pyrrolidines / pharmacology*
  • Rats
  • Signal Transduction / drug effects
  • Thiocarbamates / pharmacology*


  • NF-kappa B
  • Pyrrolidines
  • Thiocarbamates
  • pyrrolidine dithiocarbamic acid
  • Cycloheximide
  • Nitric Oxide Synthase
  • Amino Acid Oxidoreductases