Fig. 7.

Improved oxygenation and dynamic compliance in ventilated, lung-lavaged rats in vivo following the instillation of various synthetic lung surfactants. Surfactants (100 mg/kg) were instilled intratracheally into mechanically ventilated adult rats following in vivo lavage to reduce PaO₂ in 100% oxygen to <100 mm Hg, consistent with clinical ARDS (see Pulmonary Activity of Synthetic Lipid/Peptide Surfactants Containing MB/S-MB Peptides for animal model details). Synthetic surfactant containing surfactant lipids plus Super Mini-B (S-MB) peptide had the greatest activity in improving oxygenation and compliance, followed by an analogous surfactant containing Mini-B (MB). Porcine SP-B in surfactant lipids and Infasurf®, a bovine-derived clinical surfactant with both SP-B and SP-C, were studied as positive controls, while surfactant lipids alone served as a negative control.