Interference of dexamethasone with leukocyte blood volume and albumin movements in lungs from endotoxemic guinea-pigs.
Using radioactive tracers, we measured blood volume, albumin exchanges and blood leukocyte sequestration within lungs, following an intravenous injection of lipopolysaccharide (0.1-1 mg/kg). Neutrophil infiltration into the airways was followed in parallel experiments. Dexamethasone pretreatment (20 mg/kg, subcutaneous) failed to prevent early pulmonary changes induced by lipopolysaccharide as decreased blood volume, leukocyte sequestration, leukopenia or the increased trans-endothelial albumin exchanges. However, dexamethasone provided a significant protection against the later albumin leakage through the endothelial/epithelial barrier and the neutrophil accumulation in the airways observed in lipopolysaccharide-treated guinea-pigs. Our results indicate that the protective effect of dexamethasone in lipopolysaccharide-induced lung injury might derive from an initial reduction of leukocyte adhesion and a later decrease in alveolo-capillary permeability.
de Castro
C M
CM
Unité de Pharmacologie Cellulaire, Unité Associée Institut Pasteur-INSERM 285, Paris, France.
Bureau
M F
MF
Vargaftig
B B
BB
Bachelet
M
M
D000818:Animals; D001810:Blood Volume / Q000187:drug effects*; D003907:Dexamethasone / Q000494:pharmacology*; D005110:Extracellular Space / Q000378:metabolism; D005938:Glucocorticoids / Q000494:pharmacology*; D006168:Guinea Pigs; D007962:Leukocytes / Q000187:drug effects*; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008168:Lung / Q000187:drug effects* / Q000502:physiology; D008297:Male; D012709:Serum Albumin / Q000378:metabolism*
D005938:Glucocorticoids; D008070:Lipopolysaccharides; D012709:Serum Albumin; D003907:Dexamethasone