Pulmonary endothelial and epithelial integrity and neutrophil infiltration after endotoxin in interleukin-1 receptor knockout mice

• Published in: Shock (Augusta, Ga.) Ga.), 2000-02, Vol.13 (2), p.117-125
• Main Authors: SUTTON, E. T, NORMAN, J, RAO, P. S, GRAHAM, L. B, NEWTON, C. A, RICHARDS, I. S
• Format: Article
• Language: English
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Biological and medical sciences; Bronchoalveolar Lavage Fluid - cytology; Emergency and intensive care: infection, septic shock; Endothelium, Vascular - ultrastructure; Endotoxins; Escherichia coli Infections - blood; Escherichia coli Infections - chemically induced; Escherichia coli Infections - pathology; Intensive care medicine; Interleukin-6 - blood; Lung - blood supply; Lung - ultrastructure; Male; Medical sciences; Mice; Mice, Inbred C57BL; Mice, Knockout; Neutrophil Infiltration; Nitric Oxide - blood; Organelles - ultrastructure; Pulmonary Alveoli - ultrastructure; Receptors, Interleukin-1 - deficiency; Receptors, Interleukin-1 - metabolism; Receptors, Interleukin-1 Type I; Respiratory Mucosa - ultrastructure; Respiratory System - pathology; Shock, Septic - blood; Shock, Septic - chemically induced; Shock, Septic - pathology; Trachea - blood supply; Trachea - ultrastructure
• ISSN: 1073-2322; 1540-0514
• DOI: 10.1097/00024382-200013020-00005

Previously we found the structural integrity of the aortic endothelium was maintained after the administration of endotoxin in type 1 interleukin-1 (IL-1) receptor knockout mice. In this study, we investigated further the integrity of pulmonary vascular endothelium, airway epithelial, pulmonary microvasculature, and neutrophil infiltration into the microvasculature and respiratory air spaces. Adult male C57BL/129J wild-type mice and C57BL/129J knockout mice possessing a homozygous deletion of the type 1 IL-1 receptor received the following intraperitoneal injections; 1) Escherichia coli endotoxin (ENDT) (10 mg/kg), 2) ENDT (2 mg/kg given for 4 days), or (3) saline vehicle. Wild-type and knockout control animals receiving saline vehicle showed normal endothelial and epithelial ultrastructure with intact membranes. Pulmonary endothelial cell damage was found only in wild-type mice given a single 10 mg/kg endotoxin dose. Airway epithelial damage was found only in wild-type mice given a repetitive dose of endotoxin (2 mg/kg for 4 days). Neutrophil infiltration increased only in mice given a single dose of endotoxin (10 mg/kg) with the wild-type increasing by 32% and the knockouts by 6% compared with the saline control for that group respectively. Serum IL-6 and nitric oxide (indicators of septic shock severity and lethality) significantly increased only in the mice given 10 mg/kg of endotoxin. The maintenance of pulmonary endothelial and epithelial cell integrity and the decrease of neutrophil infiltration in the IL-1 knockout mice suggest that IL-1 contributes significantly to the severity of endotoxin-induced sepsis.