Experiment 2: Surfactant recovery in lung lavage and surface activity of crude LA. A: surfactant pool size of TS, LA and SA sub-fractions measured by phosphorous assay. Data are expressed as amount of phospholipids/kg body weight. Within each sub-fraction,*p < 0.05 versus the respective No Treatment condition. B: surface tension of pooled LA samples during different dynamic compression-expansion cycles. §p < 0.05 versus cycle 1 within each experimental condition. Values are expressed as mean ± SEM; n = 6 per group.