Assessment of respiratory mechanics
Twelve hours after LPS instillation into lung tissue, mice were anesthetized as described above, tracheostomized, and a rigid-type cannula (2-mm i.d.) was inserted into the trachea and firmly tied in place. The cannula was connected to a small animal ventilator (bestlab, Beijing, China) and resistance of lung (RL), resistance of expiration (Re), and respiratory lung compliance (Cdyn) of mice were measured.