Elevated permeability of the blood–brain barrier in mice intratracheally administered porcine pancreatic elastase

Chronic obstructive pulmonary disease (COPD) shows progressive, irreversible airflow limitation induced by emphysema and lung inflammation. The aim of the present study was to determine if COPD conditions induce blood–brain barrier (BBB) dysfunction. We found that the intratracheal administration of porcine pancreatic elastase (PPE; 3 U) induced alveolar enlargement, increased neutrophil number in bronchoalveolar lavage fluid, and decreased blood oxygen saturation in mice at 21 days after inhalation. In parallel with these lung damages, BBB permeability to sodium fluorescein and Evans blue albumin was markedly increased. Our findings demonstrate that COPD conditions are associated with risk for BBB impairment.