INTERLEUKIN-1-BETA-INDUCED NEUTROPHIL RECRUITMENT AND ACUTE LUNG INJURY IN HAMSTERS

Administering recombinant interleukin-1 beta (IL-1 beta) intratracheal ly caused lung neutrophil accumulation and lung injury in hamsters. Th e percentage of leukocytes that were neutrophils increased progressive ly in lavages from lungs of hamsters given 25, 50, or 100 ng IL-1 beta intratracheally 2 h before. Lung injury, reflected by increased lung lavage protein concentrations and lung lavage hemoglobin concentration s, increased 2 h after administering 100 ng IL-1 beta. Lung injury, re flected by lung wet weight/body weight ratios, followed similar patter ns, with significant increases occurring 2 h after insufflating 50 or 100 ng IL-1. Our results indicate that increased concentrations of IL- 1 beta in lung airways can cause neutrophil recruitment and lung injur y in hamsters. This mechanism may contribute to the development of lun g neutrophil accumulation and lung injury that characterizes ARDS pati ents who have increased airway levels of IL-1 beta.