Figure 3. Sheep tracheal epithelium α-ENaC without/with cigarette smoke extract (CSE) exposure. A) Western blot densitometric analysis of α-ENaC normalized to β-Actin from protein samples extracted from sheep tracheal tissue treated in vitro with or without 5% CSE in Kreb’s Ringer bicarbonate buffer. B) Demonstration of the expression of α-ENaC subunit and β-Actin as a loading control –/+ indicates treatment with 5% CSE in Kreb’s Ringer bicarbonate buffer.