Defective pulmonary recruitment of neutrophils in a rat model of endotoxemia

Am J Respir Cell Mol Biol. 1994 Dec;11(6):716-23. doi: 10.1165/ajrcmb.11.6.7524572.

Abstract

We have characterized a defect in the pulmonary recruitment of neutrophils (PMNs) in rats with experimental endotoxemia. Rats pretreated with intravenous (IV) 0.9% saline (NaCl) showed abundant PMNs in bronchoalveolar lavage (BAL) fluid after intratracheal (IT) lipopolysaccharide (LPS) (5 mg/kg) (54.27 +/- 9.80 x 10(6), n = 7, versus IT saline, 0.73 +/- 0.62 x 10(6), n = 4). In contrast, endotoxemic rats (IV LPS 1.0 mg/kg) failed to show PMN influx after IT LPS (0.40 +/- 0.13 x 10(6) PMNs in BAL fluid, n = 7). Four hours after the IT administration of LPS, the chemotactic activity of BAL fluid from endotoxemic rats (87 +/- 9.92% of maximal chemotaxis toward zymosan-activated serum [ZAS], n = 4) was not significantly different (P > 0.05), from rats pretreated with IV NaCl (61.09 +/- 6.17% of maximal chemotaxis toward ZAS, n = 4). Endotoxemic and control rats showed similar chemotactic gradients in determinations of the BAL/plasma chemotactic activity ratio (BAL/plasma ratio: 2.16 +/- 0.14, n = 4, IV NaCl versus 2.98 +/- 0.14, n = 4, IV LPS, P > 0.05). Serum from untreated rats, rats pretreated with IV NaCl, and endotoxemic rats caused minimal effects on rat PMN chemotaxis in vitro (78.17 +/- 8.16%, 79.29 +/- 7.09%, and 69.28 +/- 9.04% of maximal chemotaxis toward ZAS, respectively, n = 4/group, P > 0.05). Quantitation of PMN adhesion molecules revealed a loss of L-selectin (8 +/- 5% of control group, n = 3), an increase in Mac-1 (776 +/- 82.60% of control group, n = 3), and no change in LFA-1 when normal PMNs were incubated with plasma from rats pretreated with IV LPS (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

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

MeSH terms

  • Animals
  • Bronchoalveolar Lavage Fluid / cytology
  • Capillaries
  • Cell Adhesion Molecules / analysis
  • Cells, Cultured
  • Chemotactic Factors / metabolism
  • Chemotaxis, Leukocyte / immunology*
  • Disease Models, Animal
  • Endotoxins / blood*
  • L-Selectin
  • Lipopolysaccharides / administration & dosage
  • Lung / blood supply
  • Lung / immunology*
  • Macrophage-1 Antigen / analysis
  • Male
  • Neutrophils / chemistry
  • Neutrophils / cytology
  • Neutrophils / immunology*
  • Peritoneum / cytology
  • Pulmonary Alveoli / immunology
  • Rats
  • Receptors, Lymphocyte Homing / analysis
  • Specific Pathogen-Free Organisms
  • Toxemia / chemically induced
  • Toxemia / immunology*

Substances

  • Cell Adhesion Molecules
  • Chemotactic Factors
  • Endotoxins
  • Lipopolysaccharides
  • Macrophage-1 Antigen
  • Receptors, Lymphocyte Homing
  • L-Selectin