Figure 7: Effects of rSP-C33Leu in animal model of RDS.

Immature newborn rabbits were treated at birth with 200 mg kg⁻¹ of 2% rSP-C33Leu in DPPC:POPG (68:31, w/w) and compared to animals receiving the same dose of Curosurf as positive and non-treated animals as negative controls. The results are presented as median values±M.A.D. (median absolute deviation) as indicated by error bars, and n is the number of animals. (a) Tidal volumes were measured during 30 min of ventilation with different peak inspiratory pressures (PIP) and constant positive end-expiratory pressure (PEEP). Treatment with 2% rSP-C33Leu in DPPC:POPG or Curosurf showed similar results, with significantly increased tidal volumes compared to non-treated animals (Newman–Keuls test, P<0.0005) (b) The LGVs of animals treated with 2% rSP-C33Leu in DPPC:POPG were equal to those of animals treated with Curosurf, and significantly higher than those for non-treated animals (Newman–Keuls test, P<0.0005). (c–e) Lung appearances at the end of the experiment are shown as representative photographs of whole lungs with median LGV for (c) non-treated control animals (LGV: 0.7 ml kg^-1) and animals treated with (d) 2% rSP-C33Leu in DPPC:POPG (68:31) (LGV: 18.6 ml kg^-1) or (e) Curosurf (LGV: 18.9 ml kg^-1). Appearances of the whole set of analysed lungs are shown in Supplementary Fig. 8.