Morphometric changes of the lung induced by inhaled bacterial endotoxin.

Published

Journal Article

Due to the ubiquitous nature of airborne endotoxin, an understanding of pulmonary alterations which follow inhalation of environmentally realistic concentrations of purified bacteria derived lipopolysaccharide (LPS) is important. Using LPS derived from Enterobacter agglomerans, a bacterium found in cotton and cotton mill dust, aqueous aerosols (effective LPS concentration 4 micrograms/m3) were generated and used to expose either normal hamsters (N = 6) or those rendered endotoxin tolerant by pre-ip injection of 0.1 LD50 LPS. Control groups (normal--N = 6; tolerant--N = 6) received saline aerosol only. At 6 hr after 5-hr aerosol exposure, lungs of all animals were fixed, processed for light and transmission electron microscopy, and subject to qualitative and to multitiered morphometric analysis using standard point counting techniques. Qualitative evaluation of TEM micrographs from LPS aerosolized-nontolerant hamsters showed endothelial alteration (focal disruption, subendothelial space formation, and cytoplasmic blebbing) but volume and number of endothelial cells were not changed indicating only slight, focal endothelial damage. Quantitatively, septal capillary blood space in nontolerant, LPS aerosolized hamsters showed increased Vv of PMNs and platelets. These changes were not seen in tolerant induced-LPS aerosolized hamsters. Independent of tolerization treatment, LPS inhalation led to a decrease in fixed lung volume and an increase in numerical density of endothelial pinocytotic vesicles. It is concluded that the inhalation of realistic, environmental levels of bacterial endotoxin may induce significant changes in distal lung and may be important in the pathogenesis of byssinosis and adult respiratory distress syndrome.

Full Text

Duke Authors

Cited Authors

  • Lantz, RC; Birch, K; Hinton, DE; Burrell, R

Published Date

  • December 1985

Published In

Volume / Issue

  • 43 / 3

Start / End Page

  • 305 - 320

PubMed ID

  • 4065310

Pubmed Central ID

  • 4065310

Electronic International Standard Serial Number (EISSN)

  • 1096-0945

International Standard Serial Number (ISSN)

  • 0014-4800

Digital Object Identifier (DOI)

  • 10.1016/0014-4800(85)90068-1

Language

  • eng