Depletion of pulmonary intravascular macrophages partially inhibits lipopolysaccharide-induced lung inflammation in horses.

Horses are unique in their extreme sensitivity to endotoxin-induced cardio-pulmonary shock and mortality. The mechanisms behind increased sensitivity of the horse to endotoxin remain unknown. Pulmonary intravascular macrophages (PIMs) are pro-inflammatory cells occurring in horses.

Immunophenotypic characterization and depletion of pulmonary intravascular macrophages of horses.

Pulmonary intravascular macrophages (PIMs) are present in horses and are believed to increase their sensitivity to endotoxin-induced cardio-pulmonary shock. However, owing to a lack of a marker for PIMs and the inability to isolate them, their precise contributions in the horse remain unknown. We designed this study to identify an immuno-phenotypic marker for PIMs and to develop a protocol for their transient depletion with gadolinium chloride (GC).