Early apoptosis of monocytes contributes to the pathogenesis of systemic inflammatory response and of bacterial translocation in an experimental model of multiple trauma

Clin Exp Immunol. 2006 Jul;145(1):139-46. doi: 10.1111/j.1365-2249.2006.03112.x.


The objective of this study was to investigate the occurrence of apoptosis of monocytes in an experimental model of multiple trauma and its probable correlation to bacterial translocation. Thirty-two rabbits were applied in three groups: A, controls; B, myotomy of the right femur; and C, myotomy and fracture of the right femur. Blood was sampled for the estimation of endotoxins [lipopolysaccharide (LPS)], tumour necrosis factor (TNF)-alpha, malondialdehyde (MDA) and isolation of peripheral blood mononuclear cells (PBMCs). PBMCs, derived after centrifugation over Ficoll, were incubated in flasks and apoptosis of non-adherent lymphocytes and adherent monocytes was estimated after staining for Annexin-V and flow cytometry. TNF-alpha of supernatants of cultured monocytes was also determined. Tissue segments were cultured after death. Median survival of groups A, B and C was > 14, > 14 and 9.00 days, respectively. Apoptosis of lymphocytes in group C was higher than group A at 2, 4 and 48 h and of monocytes in group C higher than group A at 2 and 4 hours. LPS in group C was higher than group A at 2, 4 and 48 h. Apoptosis of lymphocytes and monocytes was correlated positively with serum TNF-alpha and negatively with TNF-alpha of monocyte supernatants. Cultures of organ segments of group A were sterile. Pseudomonas aeruginosa was isolated from liver, lung and spleen in five animals in group B (45.45%) and in six in group C (54.54%). Early apoptosis of blood monocytes supervened after multiple trauma; the phenomenon was accompanied by apoptosis of blood lymphocytes and subsequent bacterial translocation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Bacterial Translocation
  • Cells, Cultured
  • Fractures, Bone / immunology
  • Lipopolysaccharides / blood
  • Lymphocytes / pathology*
  • Male
  • Malondialdehyde / blood
  • Models, Animal
  • Monocytes / pathology*
  • Multiple Trauma / immunology*
  • Multiple Trauma / microbiology
  • Rabbits
  • Systemic Inflammatory Response Syndrome / immunology*
  • Systemic Inflammatory Response Syndrome / microbiology
  • Time Factors
  • Tumor Necrosis Factor-alpha / analysis


  • Lipopolysaccharides
  • Tumor Necrosis Factor-alpha
  • Malondialdehyde