Figure 4

Immuno-histochemical and immuno-cytochemical studies with normal IgG as a negative control (A), and with a monoclonal antibody against NEP (B-F). A. No staining was observed in normal lung, using non-immune IgG as negative control. B. Prominent staining for NEP was observed in the alveolar wall, particularly in normal type II alveolar epithelium. A decreased immunoreactivity for NEP was apparent in the lungs, 4 h after the instillation of HCl (C), and 24 h after the instillation of LPS (D). Immunocytochemistry of BALF cytospin preparations showed a low immunoreactivity for NEP in resident alveolar macrophages from control mice (E), and infiltrating PMN leukocytes from LPS-treated mice (F). Representative photomicrographs of lung sections and cytospin preparations from groups of 4 or 5 mice at X 400 original magnification (bar = 20 μm).