Induction of nitric oxide synthase in glial cells

J Neurochem. 1992 Sep;59(3):897-905. doi: 10.1111/j.1471-4159.1992.tb08328.x.


Primary astrocyte cultures, C6 glioma cells, and N18 neuroblastoma cells were assayed for nitric oxide synthase (NOS) activity with a bioassay of cyclic GMP production in RFL-6 fibroblasts. Treatment of astrocyte cultures for 16-18 h with lipopolysaccharide (LPS) induced NOS-like activity that was L-arginine and NADPH dependent, Ca2+ independent, and potentiated by superoxide dismutase. Induction was evident after 4 h, was dependent on the dose of LPS, and required protein synthesis. Treatment of astrocyte cultures with leucine methyl ester reduced microglial cell contamination from 7 to 1%, with a loss of 44% of NOS-like activity. C6 cells treated with LPS also showed Ca(2+)-independent and L-arginine-dependent NOS-like activity. N18 cells demonstrated constitutive Ca(2+)-dependent NOS-like activity that was not enhanced by LPS induction. These data indicate that NOS-like activity can be induced in microglia, astrocytes, and a related glioma cell line as it can in numerous other cell types, but not in neuron-like N18 cells.

Publication types

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

MeSH terms

  • Amino Acid Oxidoreductases / metabolism*
  • Animals
  • Astrocytes / enzymology
  • Cyclic GMP / metabolism
  • Enzyme Induction
  • Lipopolysaccharides
  • Neuroglia / enzymology*
  • Nitric Oxide Synthase
  • Solubility
  • Tumor Cells, Cultured


  • Lipopolysaccharides
  • Nitric Oxide Synthase
  • Amino Acid Oxidoreductases
  • Cyclic GMP