Environmental research
-
Environmental research · Dec 1992
Dose-dependent pulmonary effects of inhaled endotoxin in guinea pigs.
As a cell wall component of gram-negative bacteria, endotoxin is thought to play a significant role in the respiratory effects of inhaled organic dusts which are microbially contaminated. Assessment of occupational survey data and clinical studies suggests that few measureable, acute functional changes occur below 30-50 ng/m3 endotoxin (as sampled in airborne dust with a vertical elutriator). Little information is available on the inflammatory effects of inhaled endotoxin at these low concentrations. ⋯ Polymorphonuclear leukocyte influx into the alveolar region was also dependent on the concentration of inhaled endotoxin. Thus, LDH activity, a biochemical marker of cell injury, and total cell counts and polymorphonuclear leukocytes, markers of inflammation, were more sensitive indices of adverse pulmonary effects from inhaled endotoxin than a functional measurement. These results suggest that subtle inflammatory changes may occur at airborne endotoxin concentrations which may produce no acute respiratory symptoms.