Figure 3.

Loss of surface activity in mSplunc1-deficient airway secretions. Tracheal epithelia from Splunc1^+/+ and Splunc1^−/− mice were grown at an air-liquid interface and ASL was collected by rinsing the apical surfaces with PBS. A: The mSplunc1 protein was readily detected by immunoblotting of the apical washes from Splunc1^+/+, but not Splunc1^−/−, cultures. B: Surface activity in the samples was assessed by observing the minimum surface tension after 1 minute of pulsation in the pulsating bubble surfactometer. The mSplunc1-deficient washes displayed significantly increased surface tension relative to washes from Splunc1^+/+ animals (n = 3). *P < 0.0000001.