Effect of isoproterenol and dexamethasone on the lipopolysaccharide induced expression of CD11b on bovine neutrophils

Vet Immunol Immunopathol. 2000 Aug 31;76(1-2):151-6. doi: 10.1016/s0165-2427(00)00199-9.

Abstract

The present experiments investigate the changes in expression of CD11b on bovine neutrophils and its modulation by isopropylnoradrenaline (IPN, isoproterenol), dexamethasone (DX), phenylephrine (alpha-agonist) and clenbuterol (beta-agonist). Both IPN and DX caused a dose-dependent inhibition of LPS-induced CD11b expression. A combination of IPN and DX elicited a synergistical decrease of the CD11b expression. Clenbuterol mimicked the effect of IPN, whereas phenylephrine did not. The effect of IPN and DX could at least partly be mediated through a decreased TNF-alpha production by monocytes since tumor necrosis factor-alpha (TNF-alpha) is shown to mediate a dose-dependent CD11b up-regulation. Stimulation of stress hormone receptors partly immuno-suppresses neutrophil functions by inhibition of CD11b expression on the neutrophil surface upon LPS stimulation. This inhibition is probably related to a decrease in TNF-alpha production. A similar mechanism of immuno-suppression could contribute to the higher susceptibility of cattle to Gram-negative bacterial infections of the udder and lung during periods of stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Cell Separation / veterinary
  • Dexamethasone / pharmacology*
  • Flow Cytometry / veterinary
  • In Vitro Techniques
  • Isoproterenol / pharmacology*
  • Lipopolysaccharides / pharmacology*
  • Macrophage-1 Antigen / biosynthesis*
  • Neutrophils / drug effects
  • Neutrophils / metabolism*
  • Tumor Necrosis Factor-alpha / pharmacology
  • Up-Regulation

Substances

  • Lipopolysaccharides
  • Macrophage-1 Antigen
  • Tumor Necrosis Factor-alpha
  • Dexamethasone
  • Isoproterenol