A murine model of pulmonary damage induced by lipopolysaccharide via intranasal instillation

This study examines the intranasal instillation of lipopolysaccharide (LPS) into BALB/c mice causing acute pulmonary damage, due to neutrophil infiltration and sepsis. A dose response with LPS showed that an intranasal instillation of 167 microg/ml (10 microg/mouse) caused acute lung injury within 2-4 h and reached maximal damage at 24-48 h. We found the method of LPS administration for induction of acute pulmonary damage to be crucial. After 24 h post-LPS injection, a comparison showed a substantial increase in pulmonary damage with intranasal instillation of LPS. As for intravenous injection, it showed a baseline effect. This study indicates that LPS administered intranasally causes acute pulmonary damage, whereas with intravenous and intraperitoneal endotoxin administration a tissue-specific or similar degree of pulmonary injury may not develop.