Intranasal SEA challenge induces lung injury and leukocyte infiltrate.

<p>Mice received 1 <i>µ</i>g of SEA diluted in BSS (Vehicle) through the i.n. route. (A) Lungs from day 2 SEA challenged mice were isolated, sectioned, and stained with H&E. Left panels display a low magnification (100X) and right panels high magnification (400X) of representative lung sections. Black arrows indicate leakage of red blood cells, white arrows indicate eosin staining refractile material (protein). (B) High magnification (400X) of lungs with (left panel) and without perfusion (right panel) of representative lung sections after vehicle alone and SEA i.n inhalation. Arrows indicate infiltrating leukocytes retained in blood vessel after perfusion. (C) Electron microscopy of lung blood vessels after vehicle alone and SEA i.n inhalation: Alveoli (Alv), Blood Vessel (B.Ves.), Erythrocyte (e), Leukocyte (L), Transmigrating leukocyte (L*). Bar = 10 µm. The data are representative of three independent experiments using 2–4 mice per group.