The Use of Reuber Hepatoma Cells for the Study of a Lipopolysaccharide-Induced Macrophage Factor: Glucocorticoid-Antagonizing Factor

Lab Invest. 1979 Aug;41(2):174-81.

Abstract

Endotoxin-stimulated glucocorticoid-antagonizing factor (GAF) was assayed by its specific inhibition of hydrocortisone-induced synthesis of phosphoenolpyruvate carboxykinase. Defined induction of phosphoenolpyruvate carboxykinase synthesis in hydrocortisone-treated rat hepatoma cells permitted reliable quantitation of GAF and analysis of the mechanism of cortisol antagonism. GAF was present maximally in serum 2 hours after endotoxin challenge in mice; however, GAF production could be suppressed by pretreating mice with indomethacin or cortisol. Endotoxin-tolerant mice were also nonresponsive to endotoxin-stimulated GAF production. Gel filtration on Sephadex G-200 resolved four regions of glucocorticoid-antagonizing activity in serum from endotoxin-poisoned mice, two of which were not present in normal serum. Cortisol antagonism by GAF resembled that of insulin; however, insulin differed from GAF in its ability to antagonize dibutyryl cyclic AMP. Unlike insulin, endotoxin-induced serum glucocorticoid-antagonizing activity was heat-labile at 70 degrees C. GAF antagonism of hydrocortisone was partially reversible but did not act in a competitive manner. Production of hepatoma growth inhibitory activity and glucocorticoid-antagonizing activity in serum were closely associated, indicating a common methanism for their generation.

Publication types

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

MeSH terms

  • Animals
  • Blood Proteins / biosynthesis*
  • Cell Line
  • Endotoxins
  • Enzyme Induction
  • Glucocorticoids / antagonists & inhibitors*
  • Hydrocortisone / antagonists & inhibitors
  • Hydrocortisone / pharmacology
  • Indomethacin / pharmacology
  • Insulin / pharmacology
  • Macrophages / metabolism*
  • Mice
  • Phosphoenolpyruvate Carboxykinase (GTP) / biosynthesis

Substances

  • Blood Proteins
  • Endotoxins
  • Glucocorticoids
  • Insulin
  • Phosphoenolpyruvate Carboxykinase (GTP)
  • Hydrocortisone
  • Indomethacin