Figure 2: Lung histology. Representative photomicrographs of lung parenchyma stained with hematoxylin and eosin from (a) pulmonary ARDS (ARDSp) and (b) extrapulmonary ARDS (ARDSexp) animals. ARDS was induced by administration of Escherichia coli lipopolysaccharide intratracheally (ARDSp) or intraperitoneally (ARDSexp). Control mice (C) received saline solution intratracheally (Cp) or intraperitoneally (Cexp). After 24 h, ARDSp and ARDSexp animals were further randomized to receive saline (50 μL, SAL), bone marrow-derived MSCs (105, 50 μL), or EVs (105, 50 μL), stimulated (MSC serum, EV serum) or not (MSCs, EVs) with serum obtained from ARDSp or ARDSexp animals.